Get all linked geometries from Assembly Instance

Hi smart guys!

I would like to get some answers how to get elements’ geometries from a assembly instance.

I am dealing with a Revit file for pre-cast concrete things and each finalized slab is model assembly(base slab element, penetrations, and extra) … I have been able to select all assembly instances by using Element Types > All Elements of Type nodes but after that, Element.Gemetry node returns just empty lists.

I am assuming there should be a way of accessing linked or child elements to it by either Dynamo node or custom script(either in C# or Python) with Revit API.

Does anyone know how to do that?