diff --git a/src/bonsai/bonsai/bim/module/geometry/operator.py b/src/bonsai/bonsai/bim/module/geometry/operator.py
index 9bc0566532..6d62d6cccf 100644
--- a/src/bonsai/bonsai/bim/module/geometry/operator.py
+++ b/src/bonsai/bonsai/bim/module/geometry/operator.py
@@ -1531,8 +1531,13 @@ class DuplicateMoveLinkedAggregate(bpy.types.Operator):
             old_to_new = OverrideDuplicateMove.execute_ifc_duplicate_operator(self, context, linked=True)
             all_old_to_new.update(old_to_new)  # Collect all duplicates
 
-            # Recreate aggregate structure
-            tool.Root.recreate_aggregate(old_to_new)
+            # Note: execute_ifc_duplicate_operator() above already recreates the aggregate
+            # structure for us (including reassigning to an unduplicated parent aggregate, see
+            # its "Restore parent aggregate relationships" step). Calling
+            # tool.Root.recreate_aggregate() again here is not just redundant: since the parent
+            # aggregate is never part of `old_to_new` when it wasn't itself duplicated,
+            # recreate_aggregate()'s "parent not found" branch actively *unassigns* the just
+            # restored parent link, stranding a duplicated nested aggregate outside its parent (#6663).
 
             # Copy linked aggregate data
             copy_linked_aggregate_data(old_to_new)
diff --git a/src/bonsai/test/bim/feature/geometry.feature b/src/bonsai/test/bim/feature/geometry.feature
index 1236f416c8..fa2a1dbafd 100644
--- a/src/bonsai/test/bim/feature/geometry.feature
+++ b/src/bonsai/test/bim/feature/geometry.feature
@@ -610,6 +610,21 @@ Scenario: Duplicate linked aggregate
     And the object "Assembly_01" exists
     Then the object "IfcElementAssembly/Assembly" and "Assembly_01" belong to the same Linked Aggregate Group
 
+Scenario: Duplicate linked aggregate - a nested aggregate stays inside its parent aggregate
+    Given I load the IFC test file "/test/files/linked-aggregates.ifc"
+    And the object "IfcWall/Wall_01" is selected
+    And additionally the object "IfcWall/Wall_02" is selected
+    When I press "bim.add_aggregate(aggregate_name='Nested')"
+    Then the object "IfcElementAssembly/Nested" is aggregated by object "IfcElementAssembly/Assembly"
+    When the object "IfcWall/Wall_01" is selected
+    And I duplicate linked aggregate the selected objects
+    Then the object "IfcWall/Wall_01.001" exists
+    And the object "IfcWall/Wall_02.001" exists
+    # msgbus updates don't happen in background mode, so obj is not renamed to "IfcElementAssembly/Nested_01"
+    And the object "Nested_01" exists
+    And the object "IfcWall/Wall_01.001" is aggregated by object "Nested_01"
+    And the object "Nested_01" is aggregated by object "IfcElementAssembly/Assembly"
+
 Scenario: Refresh linked aggregate
     Given I load the IFC test file "/test/files/linked-aggregates.ifc"
     And the object "IfcWall/Wall_01" is selected