diff --git a/frontend/components/category/CategoriesDialog.tsx b/frontend/components/category/CategoriesDialog.tsx
index 40bac32ad..d7cdd3af9 100644
--- a/frontend/components/category/CategoriesDialog.tsx
+++ b/frontend/components/category/CategoriesDialog.tsx
@@ -3,10 +3,11 @@
 //
 // SPDX-License-Identifier: Apache-2.0
 
+import {useEffect, useState} from 'react'
+
 import Dialog from '@mui/material/Dialog'
 import DialogContent from '@mui/material/DialogContent'
 import DialogTitle from '@mui/material/DialogTitle'
-import Alert from '@mui/material/Alert'
 import DialogActions from '@mui/material/DialogActions'
 import Button from '@mui/material/Button'
 import useMediaQuery from '@mui/material/useMediaQuery'
@@ -14,9 +15,7 @@ import SaveIcon from '@mui/icons-material/Save'
 
 import {TreeNode} from '~/types/TreeNode'
 import {CategoryEntry} from '~/types/Category'
-import ContentLoader from '../layout/ContentLoader'
-import {RecursivelyGenerateItems} from '~/components/software/TreeSelect'
-import {useEffect, useState} from 'react'
+import CategoriesDialogBody from './CategoriesDialogBody'
 
 type CategoriesDialogProps={
   title: string,
@@ -37,11 +36,11 @@ export default function CategoriesDialog({
   const smallScreen = useMediaQuery('(max-width:600px)')
   const [selectedCategoryIds, setSelectedCategoryIds] = useState<Set<string>>(new Set())
 
-  // console.group('CategoriesDialog')
-  // console.log('state...', state)
-  // console.log('selected...', selected)
-  // console.log('selectedCategoryIds...',selectedCategoryIds)
-  // console.groupEnd()
+  console.group('CategoriesDialog')
+  console.log('state...', state)
+  console.log('selected...', selected)
+  console.log('selectedCategoryIds...',selectedCategoryIds)
+  console.groupEnd()
 
   useEffect(()=>{
     if (state==='ready'){
@@ -49,72 +48,10 @@ export default function CategoriesDialog({
     }
   },[selected,state])
 
-  function isSelected(node: TreeNode<CategoryEntry>) {
-    const val = node.getValue()
-    return selectedCategoryIds.has(val.id)
-  }
-
-  function textExtractor(value: CategoryEntry) {
-    return value.name
-  }
-
-  function keyExtractor(value: CategoryEntry) {
-    return value.id
-  }
-
-  function onSelect(node: TreeNode<CategoryEntry>) {
-    const val = node.getValue()
-    if (selectedCategoryIds.has(val.id)) {
-      selectedCategoryIds.delete(val.id)
-    } else {
-      selectedCategoryIds.add(val.id)
-    }
-    setSelectedCategoryIds(new Set(selectedCategoryIds))
-  }
-
   function isSaveDisabled(){
     return categories === null || categories.length === 0 || state !== 'ready'
   }
 
-  function renderDialogContent(): JSX.Element {
-    switch (state) {
-      case 'loading':
-      case 'saving':
-        return (
-          <div className="flex-1 flex justify-center items-center">
-            <ContentLoader/>
-          </div>
-        )
-
-      case 'error':
-        return (
-          <Alert severity="error" sx={{marginTop: '0.5rem'}}>
-            {errorMsg ?? '500 - Unexpected error'}
-          </Alert>
-        )
-
-      case 'ready':
-        return (
-          <>
-            {(categories === null || categories.length === 0)
-              ?
-              <Alert severity="info" sx={{'padding': '2rem'}}>
-                {noItemsMsg}
-              </Alert>
-              :
-              <RecursivelyGenerateItems
-                nodes={categories}
-                isSelected={isSelected}
-                keyExtractor={keyExtractor}
-                onSelect={onSelect}
-                textExtractor={textExtractor}
-              />
-            }
-          </>
-        )
-    }
-  }
-
   return (
     <Dialog open fullScreen={smallScreen}>
       <DialogTitle sx={{
@@ -131,7 +68,14 @@ export default function CategoriesDialog({
           padding: '1rem 1.5rem 2.5rem !important',
         }}>
 
-        {renderDialogContent()}
+        <CategoriesDialogBody
+          categories={categories}
+          state={state}
+          errorMsg={errorMsg}
+          noItemsMsg={noItemsMsg}
+          selectedCategoryIds={selectedCategoryIds}
+          setSelectedCategoryIds={setSelectedCategoryIds}
+        />
 
       </DialogContent>
       <DialogActions sx={{
diff --git a/frontend/components/category/CategoriesDialogBody.tsx b/frontend/components/category/CategoriesDialogBody.tsx
new file mode 100644
index 000000000..67d35b76e
--- /dev/null
+++ b/frontend/components/category/CategoriesDialogBody.tsx
@@ -0,0 +1,94 @@
+// SPDX-FileCopyrightText: 2024 Dusan Mijatovic (Netherlands eScience Center)
+// SPDX-FileCopyrightText: 2024 Netherlands eScience Center
+//
+// SPDX-License-Identifier: Apache-2.0
+
+import Alert from '@mui/material/Alert'
+import {CategoryEntry} from '~/types/Category'
+import {TreeNode} from '~/types/TreeNode'
+import ContentLoader from '../layout/ContentLoader'
+import {CategoryList} from './CategoryList'
+import List from '@mui/material/List'
+
+type CategoriesDialogBodyProps={
+  categories: TreeNode<CategoryEntry>[],
+  state: 'loading' | 'error' | 'ready' | 'saving',
+  errorMsg: string | null
+  noItemsMsg: string
+  selectedCategoryIds: Set<string>,
+  setSelectedCategoryIds: (ids:Set<string>)=>void
+}
+
+export default function CategoriesDialogBody({
+  categories,state,errorMsg,noItemsMsg,
+  selectedCategoryIds, setSelectedCategoryIds
+}:CategoriesDialogBodyProps) {
+
+
+  function isSelected(node: TreeNode<CategoryEntry>) {
+    const val = node.getValue()
+    // default approach
+    // return selectedCategoryIds.has(val.id)
+
+    // ALTERNATIVE APPROACH
+    // directly selected
+    if (selectedCategoryIds.has(val.id)) return true
+
+    // any of children selected?
+    const found = node.children().find(item=>{
+      return isSelected(item)
+    })
+    // debugger
+    if (found) return true
+    // none of children selected either
+    return false
+  }
+
+  function onSelect(node: TreeNode<CategoryEntry>) {
+    const val = node.getValue()
+    if (selectedCategoryIds.has(val.id)) {
+      selectedCategoryIds.delete(val.id)
+    } else {
+      selectedCategoryIds.add(val.id)
+    }
+    setSelectedCategoryIds(new Set(selectedCategoryIds))
+  }
+
+  switch (state) {
+    case 'loading':
+    case 'saving':
+      return (
+        <div className="flex-1 flex justify-center items-center">
+          <ContentLoader/>
+        </div>
+      )
+
+    case 'error':
+      return (
+        <Alert severity="error" sx={{marginTop: '0.5rem'}}>
+          {errorMsg ?? '500 - Unexpected error'}
+        </Alert>
+      )
+
+    case 'ready':
+      return (
+        <>
+          {(categories === null || categories.length === 0)
+            ?
+            <Alert severity="info" sx={{'padding': '2rem'}}>
+              {noItemsMsg}
+            </Alert>
+            :
+            <List>
+              <CategoryList
+                categories={categories}
+                isSelected={isSelected}
+                onSelect={onSelect}
+              />
+            </List>
+          }
+        </>
+      )
+  }
+
+}
diff --git a/frontend/components/category/CategoryList.tsx b/frontend/components/category/CategoryList.tsx
new file mode 100644
index 000000000..f64599e80
--- /dev/null
+++ b/frontend/components/category/CategoryList.tsx
@@ -0,0 +1,127 @@
+// SPDX-FileCopyrightText: 2024 Dusan Mijatovic (Netherlands eScience Center)
+// SPDX-FileCopyrightText: 2024 Netherlands eScience Center
+//
+// SPDX-License-Identifier: Apache-2.0
+
+import {useState} from 'react'
+import ExpandLess from '@mui/icons-material/ExpandLess'
+import ExpandMore from '@mui/icons-material/ExpandMore'
+import Checkbox from '@mui/material/Checkbox'
+import Collapse from '@mui/material/Collapse'
+import IconButton from '@mui/material/IconButton'
+import List from '@mui/material/List'
+import ListItem from '@mui/material/ListItem'
+import ListItemButton from '@mui/material/ListItemButton'
+import ListItemText from '@mui/material/ListItemText'
+
+import {TreeNode} from '~/types/TreeNode'
+import {CategoryEntry} from '~/types/Category'
+
+type NodeWithChildrenProps = {
+  node: TreeNode<CategoryEntry>
+  onSelect: (node: TreeNode<CategoryEntry>) => void
+  isSelected: (node: TreeNode<CategoryEntry>) => boolean
+}
+
+function NodeWithChildren({
+  node,
+  isSelected,
+  onSelect
+}:NodeWithChildrenProps){
+  // open/close children panel
+  const [open,setOpen] = useState(true)
+  // get category
+  const cat = node.getValue()
+
+  return (
+    <>
+      <ListItem
+        key={cat.id}
+        title={cat.short_name}
+        secondaryAction={
+          <IconButton
+            edge="end"
+            aria-label="expand"
+            onClick={()=>setOpen(!open)}
+          >
+            {open ? <ExpandLess /> : <ExpandMore />}
+          </IconButton>
+        }
+        disablePadding
+        dense
+      >
+        <ListItemButton onClick={() => onSelect(node)}>
+          <Checkbox disableRipple checked={isSelected(node)} />
+          <ListItemText
+            primary={cat.name}
+            // secondary={cat.name}
+          />
+        </ListItemButton>
+      </ListItem>
+      {/* Children block */}
+      <Collapse
+        in={open}
+        timeout="auto"
+        unmountOnExit={false}
+      >
+        <List sx={{pl:'1rem'}}>
+          <CategoryList
+            categories={node.children()}
+            onSelect={onSelect}
+            isSelected={isSelected}
+          />
+        </List>
+      </Collapse>
+    </>
+  )
+}
+
+export type CategoryListProps = {
+  onSelect: (node: TreeNode<CategoryEntry>) => void
+  isSelected: (node: TreeNode<CategoryEntry>) => boolean
+  categories: TreeNode<CategoryEntry>[]
+}
+
+export function CategoryList({
+  categories,
+  isSelected,
+  onSelect
+}: CategoryListProps) {
+  // loop all categories
+  return categories.map(node => {
+    const cat = node.getValue()
+
+    // single cat element without children
+    if (node.childrenCount() === 0) {
+      return (
+        <ListItem
+          key={cat.id}
+          // title={cat.name}
+          title={cat.short_name}
+          disablePadding
+          dense
+        >
+          <ListItemButton onClick={() => onSelect(node)}>
+            <Checkbox
+              disableRipple
+              checked={isSelected(node)}
+            />
+            <ListItemText
+              primary={cat.name}
+              // secondary={cat.name}
+            />
+          </ListItemButton>
+        </ListItem>
+      )
+    }
+
+    return (
+      <NodeWithChildren
+        key={cat.id}
+        node={node}
+        isSelected={isSelected}
+        onSelect={onSelect}
+      />
+    )
+  })
+}
diff --git a/frontend/components/software/TreeSelect.tsx b/frontend/components/category/TreeSelect.tsx
similarity index 96%
rename from frontend/components/software/TreeSelect.tsx
rename to frontend/components/category/TreeSelect.tsx
index 0b1acd767..35c29e70f 100644
--- a/frontend/components/software/TreeSelect.tsx
+++ b/frontend/components/category/TreeSelect.tsx
@@ -1,3 +1,4 @@
+// SPDX-FileCopyrightText: 2024 Dusan Mijatovic (Netherlands eScience Center)
 // SPDX-FileCopyrightText: 2024 Ewan Cahen (Netherlands eScience Center) <e.cahen@esciencecenter.nl>
 // SPDX-FileCopyrightText: 2024 Netherlands eScience Center
 //
diff --git a/frontend/components/software/edit/communities/CommunityAddCategoriesDialog.tsx b/frontend/components/software/edit/communities/CommunityAddCategoriesDialog.tsx
index 1e7e48e22..31ee3d68e 100644
--- a/frontend/components/software/edit/communities/CommunityAddCategoriesDialog.tsx
+++ b/frontend/components/software/edit/communities/CommunityAddCategoriesDialog.tsx
@@ -13,7 +13,7 @@ import {CategoryEntry} from '~/types/Category'
 import ContentLoader from '~/components/layout/ContentLoader'
 import Alert from '@mui/material/Alert'
 import {loadCategoryRoots} from '~/components/category/apiCategories'
-import {RecursivelyGenerateItems} from '~/components/software/TreeSelect'
+import {RecursivelyGenerateItems} from '~/components/category/TreeSelect'
 import {CategoryForSoftwareIds} from '~/types/SoftwareTypes'
 import DialogActions from '@mui/material/DialogActions'
 import Button from '@mui/material/Button'
diff --git a/frontend/components/software/edit/links/AutosaveSoftwareCategories.tsx b/frontend/components/software/edit/links/AutosaveSoftwareCategories.tsx
index e74d489e2..e0c40694a 100644
--- a/frontend/components/software/edit/links/AutosaveSoftwareCategories.tsx
+++ b/frontend/components/software/edit/links/AutosaveSoftwareCategories.tsx
@@ -9,7 +9,7 @@
 import {Fragment, useMemo, useState} from 'react'
 import {CategoryEntry} from '~/types/Category'
 import {categoryTreeNodesSort, ReorderedCategories} from '~/utils/categories'
-import TreeSelect from '~/components/software/TreeSelect'
+import TreeSelect from '~/components/category/TreeSelect'
 import {TreeNode} from '~/types/TreeNode'
 import {addCategoryToSoftware, deleteCategoryToSoftware} from '~/utils/getSoftware'
 import {useSession} from '~/auth'
diff --git a/frontend/components/software/edit/organisations/useSoftwareCategories.tsx b/frontend/components/software/edit/organisations/useSoftwareCategories.tsx
index e484c1f11..a66a66386 100644
--- a/frontend/components/software/edit/organisations/useSoftwareCategories.tsx
+++ b/frontend/components/software/edit/organisations/useSoftwareCategories.tsx
@@ -47,9 +47,9 @@ export default function useSoftwareCategories({
           const availableIds = new Set<string>()
           categories.forEach(root=>{
             root.forEach(node=>{
-              if (node.children().length === 0) {
-                availableIds.add(node.getValue().id)
-              }
+              // if (node.children().length === 0) {
+              availableIds.add(node.getValue().id)
+              // }
             })
           })
           if (abort) return