Create 3D rooms from linked file

Hi,

I’m having some trouble. I’m trying to create 3D rooms from linked files but it dosen’t work. I can create some Import Symbols but I would like to create a mass or something else I can messure from.

There is several linked models in my model. Is it possible to choose one of them to extract the rooms from? Right now it only picks a random model.

This is what I’ve done so far.

Dynamo linked model