extends bim.select_type by selecting multiple types from a selection of objects.

Also when the type is selected and turned on, all other types are automatically turned off.
https://imgur.com/a/DQUF0ai

src/blenderbim/blenderbim/bim/import_ifc.py

@@ -1498,7 +1498,11 @@ class IfcImporter:
             # Occurs when reloading a project
             pass
         project_collection = bpy.context.view_layer.layer_collection.children[self.project["blender"].name]
-        project_collection.children[self.type_collection.name].hide_viewport = True
+        types_collection = project_collection.children[self.type_collection.name]
+        types_collection.hide_viewport = False
+        for obj in types_collection.collection.objects: #turn off all objects inside Types collection.
+            obj.hide_set(True)
+
 
     def clean_mesh(self):
         obj = None

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

@@ -134,7 +134,6 @@ class LaunchTypeManager(bpy.types.Operator):
             op = row.operator("bim.rename_type", icon="GREASEPENCIL", text="")
             op.element = relating_type["id"]
             op = row.operator("bim.select_type", icon="OBJECT_DATA", text="")
-            op.relating_type = relating_type["id"]
             op = row.operator("bim.duplicate_type", icon="DUPLICATE", text="")
             op.element = relating_type["id"]
             op = row.operator("bim.remove_type", icon="X", text="")

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

@@ -146,21 +146,39 @@ class SelectType(bpy.types.Operator):
     relating_type: bpy.props.IntProperty()
 
     def execute(self, context):
-        element = tool.Ifc.get().by_id(self.relating_type)
-        obj = tool.Ifc.get_object(element)
-        if obj:
-            try:
-                tool.Blender.select_and_activate_single_object(context, obj)
-            except:
-                self.report({"INFO"}, "Type object is hidden.")
-        # IfcTypeProducts are only used for annotations and not part of the model interface.
-        if element.is_a() != "IfcTypeProduct":
-            try:
-                context.scene.BIMModelProperties.ifc_class = element.is_a()
-                context.scene.BIMModelProperties.relating_type_id = str(self.relating_type)
-            except:
-                # Potentially our BIM Tool is filtered to a specific element.
-                pass
+        selected_objs = context.selected_objects
+        active_obj = context.active_object
+        selected_objs.append(active_obj) #update selected_objs so the active_obj is at the end of the list
+        last_relating_type_obj = None
+        types_collection = bpy.data.collections.get("Types")
+        for obj in types_collection.objects:
+            obj.hide_set(True)
+        for obj in selected_objs:
+            element = tool.Ifc.get_entity(obj)
+            relating_type = ifcopenshell.util.element.get_type(element)
+            relating_type_obj = tool.Ifc.get_object(relating_type)
+            obj.select_set(False)
+            if relating_type_obj:
+                if relating_type_obj.hide_get():  
+                    relating_type_obj.hide_set(False)  
+                relating_type_obj.select_set(True)  
+                last_relating_type_obj = relating_type_obj 
+
+        context.view_layer.objects.active = last_relating_type_obj #make the active_obj's type the active object
+        
+            # if relating_type_obj:
+            #     try:
+            #         tool.Blender.select_and_activate_single_object(context, relating_type_obj)
+            #     except:
+            #         self.report({"INFO"}, "Type object is hidden.")
+            # # IfcTypeProducts are only used for annotations and not part of the model interface.
+            # if element.is_a() != "IfcTypeProduct":
+            #     try:
+            #         context.scene.BIMModelProperties.ifc_class = element.is_a()
+            #         context.scene.BIMModelProperties.relating_type_id = str(relating_type)
+            #     except:
+            #         # Potentially our BIM Tool is filtered to a specific element.
+            #         pass
         return {"FINISHED"}