Finding stacked Brep overlap

I don’t really understand why you have brep that are quite overlapping and others that doesn’t touch, except if you put a big tolerance.
Here is a way to take into account your “strange” “bad” modeling.

  1. First extract just closed brep edges.
  2. Then group them by plane using Nautilus “Group Curves by plane” with a big tolerance.
  3. Project the curves on a same plane in order to have a region intersection working
  4. Then use region intersection (27.7 KB)

And link to your reference question, how do you think you could get an answer with just some screen capture !!!