Here is the Autodesk solution:
Issue:You want to display cut 3D drawing models in section views. Revit displays the entire drawing without regard to cutting plane, both in section and floor plan views.
Causes:Revit cannot currently display cut 3D drawing models in section views.
- In AutoCAD, run EXPORTTOAUTOCAD to export a DWG file.
- Import or link the DWG file into an in-place family.
3D drawing is not being cut in section or elevation in Revit | Revit Products | Autodesk Knowledge Network