Better solution but I didn't test it and it's a bit more complex

vizro-core/examples/demo/app.py

@@ -34,14 +34,11 @@ class CustomNavLink(vm.NavLink):
     """Custom NavLink that uses CollapsedAccordion."""
 
     type: Literal["custom_nav_link"] = "custom_nav_link"
+    nav_selector: vm.Accordion = None
 
     def pre_build(self):
-        self._nav_selector = CollapsedAccordion(pages=self.pages)
-
-    # This isn't doing anything - you can remove it
-    # def build(self, *, active_page_id=None):
-    #     nav_link_build_obj = super().build()
-    #     return nav_link_build_obj
+        self._nav_selector = self.nav_selector or vm.Accordion()
+        self._nav_selector.pages = self.nav_selector.pages or self.pages
 
 
 gapminder = px.data.gapminder()
@@ -570,11 +567,13 @@ def create_home_page():
     navigation=vm.Navigation(
         nav_selector=vm.NavBar(
             items=[
-                CustomNavLink(label="Homepage", pages=["Homepage"], icon="Home"),
+                CustomNavLink(label="Homepage", pages=["Homepage"], icon="Home"),  # Leave this with the default
+                # Accordion() (which won't appear because there's only one page)
                 CustomNavLink(
                     label="Analysis",
                     pages=["Variable Analysis", "Relationship Analysis", "Benchmark Analysis"],
                     icon="Stacked Bar Chart",
+                    nav_selector=CollapsedAccordion(),  # Set to CollapsedAccordion() to override Accordion() default
                 ),
                 CustomNavLink(label="Summary", pages=["Continent Summary"], icon="Globe"),
             ]