You can now select only the aggregate or the aggregate and all its part using the interface

src/blenderbim/blenderbim/bim/module/aggregate/operator.py

@@ -96,7 +96,7 @@ class BIM_OT_aggregate_unassign_object(bpy.types.Operator, Operator):
             )
 
             # Removes Pset related to Linked Aggregates
-            pset = ifcopenshell.util.element.get_pset(element, 'BBIM_Linked_Aggregate')
+            pset = ifcopenshell.util.element.get_pset(element, "BBIM_Linked_Aggregate")
             if pset:
                 pset = tool.Ifc.get().by_id(pset["id"])
                 ifcopenshell.api.run("pset.remove_pset", tool.Ifc.get(), pset=pset)
@@ -206,15 +206,29 @@ class BIM_OT_select_aggregate(bpy.types.Operator):
     bl_label = "Select Aggregate"
     bl_options = {"REGISTER", "UNDO"}
     obj: bpy.props.StringProperty()
+    select_parts: bpy.props.BoolProperty(default=False)
+
+    @classmethod
+    def description(cls, context, properties):
+        if properties.select_parts:
+            return "Select Aggregate and Parts"
+        else:
+            return "Select Aggregate"
 
     def execute(self, context):
         self.file = IfcStore.get_file()
         obj = bpy.data.objects.get(self.obj) or context.active_object
         aggregate = ifcopenshell.util.element.get_aggregate(tool.Ifc.get_entity(obj))
         aggregate_obj = tool.Ifc.get_object(aggregate)
+        if self.select_parts:
+            bpy.ops.bim.select_parts(obj=aggregate_obj.name)
         if aggregate_obj in context.selectable_objects:
-            aggregate_obj.select_set(True)
+            tool.Blender.set_objects_selection(
-            bpy.context.view_layer.objects.active = aggregate_obj
+                context,
+                aggregate_obj,
+                [aggregate_obj],
+                clear_previous_selection=not self.select_parts,
+            )
         return {"FINISHED"}
 
 
@@ -242,6 +256,7 @@ class BIM_OT_add_part_to_object(bpy.types.Operator, Operator):
             part_name=self.part_name,
         )
 
+
 class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, Operator):
     bl_idname = "bim.break_link_to_other_aggregates"
     bl_label = "Break link to other aggregates"
@@ -258,7 +273,7 @@ class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, Operator):
         parts = ifcopenshell.util.element.get_parts(aggregate)
 
         for part in parts:
-            pset = ifcopenshell.util.element.get_pset(part, 'BBIM_Linked_Aggregate')
+            pset = ifcopenshell.util.element.get_pset(part, "BBIM_Linked_Aggregate")
             pset = tool.Ifc.get().by_id(pset["id"])
             ifcopenshell.api.run("pset.remove_pset", tool.Ifc.get(), pset=pset)
 
@@ -272,6 +287,7 @@ class BIM_OT_break_link_to_other_aggregates(bpy.types.Operator, Operator):
 
         return {"FINISHED"}
 
+
 class BIM_OT_select_linked_aggregates(bpy.types.Operator, Operator):
     bl_idname = "bim.select_linked_aggregates"
     bl_label = "Select linked aggregates"

src/blenderbim/blenderbim/bim/module/aggregate/ui.py

@@ -62,8 +62,12 @@ class BIM_PT_aggregate(Panel):
             row = layout.row(align=True)
             if AggregateData.data["has_relating_object"]:
                 row.label(text=AggregateData.data["relating_object_label"], icon="TRIA_UP")
+                op = row.operator("bim.select_aggregate", icon="OBJECT_DATA", text="")
+                op.obj = context.active_object.name
+                op.select_parts = False
                 op = row.operator("bim.select_aggregate", icon="RESTRICT_SELECT_OFF", text="")
                 op.obj = context.active_object.name
+                op.select_parts = True
                 row.operator("bim.enable_editing_aggregate", icon="GREASEPENCIL", text="")
                 row.operator("bim.add_aggregate", icon="ADD", text="")
                 op = row.operator("bim.aggregate_unassign_object", icon="X", text="")