diff --git a/client/src/app/infrastructure/definitions/tree.ts b/client/src/app/infrastructure/definitions/tree.ts
index 03f19767c4..d950bacdac 100644
--- a/client/src/app/infrastructure/definitions/tree.ts
+++ b/client/src/app/infrastructure/definitions/tree.ts
@@ -21,6 +21,7 @@ export interface TreeNodeWithoutItem extends TreeIdNode {
 export interface OSTreeNode<T> extends TreeNodeWithoutItem {
     item: T;
     children?: OSTreeNode<T>[];
+    toString: () => string;
 }
 
 /**
@@ -46,6 +47,7 @@ export type FlatNode<T> = T & {
     expandable: boolean;
     id: number;
     filtered?: boolean;
+    toString: () => string;
 };
 
 function isIdentifiedItemNode(obj: any): boolean {
diff --git a/client/src/app/site/pages/meetings/pages/motions/pages/motion-detail/components/motion-content/motion-content.component.html b/client/src/app/site/pages/meetings/pages/motions/pages/motion-detail/components/motion-content/motion-content.component.html
index 74912c2ded..82cd9fdf1a 100644
--- a/client/src/app/site/pages/meetings/pages/motions/pages/motion-detail/components/motion-content/motion-content.component.html
+++ b/client/src/app/site/pages/meetings/pages/motions/pages/motion-detail/components/motion-content/motion-content.component.html
@@ -182,6 +182,7 @@
                 formControlName="category_id"
                 placeholder="{{ 'Category' | translate }}"
                 [repo]="categoryRepo"
+                [excludeIds]="true"
             ></os-repo-search-selector>
         </mat-form-field>
     </div>
diff --git a/client/src/app/ui/modules/sorting/modules/sorting-tree/services/tree.service.ts b/client/src/app/ui/modules/sorting/modules/sorting-tree/services/tree.service.ts
index 84fb1933bd..ea6f5d0135 100644
--- a/client/src/app/ui/modules/sorting/modules/sorting-tree/services/tree.service.ts
+++ b/client/src/app/ui/modules/sorting/modules/sorting-tree/services/tree.service.ts
@@ -31,7 +31,10 @@ export class TreeService {
             name: item.getTitle(),
             id: item.id,
             item,
-            children
+            children,
+            toString: function () {
+                return this.item.toString();
+            }
         };
     }
 
@@ -352,7 +355,10 @@ export class TreeService {
             isSeen: true,
             expandable: false,
             id: item.id,
-            position: index + oldMaxPosition + 1
+            position: index + oldMaxPosition + 1,
+            toString: function () {
+                return this.item.toString();
+            }
         }));
         return tree.concat(items);
     }
@@ -406,7 +412,10 @@ export class TreeService {
             expandable: !!children,
             isExpanded: !!children,
             level,
-            isSeen: true
+            isSeen: true,
+            toString: function () {
+                return this.item.toString();
+            }
         };
         return new Proxy(node, {
             get: (target: FlatNode<T>, property: keyof Identifiable & Displayable & T) => {