Trim surfaces with one brep

Hi, I’m trying to cut a pattern made by solid hatch (surface) inside a proper rectangle, but the only thing I can do is to have cut curves (trim woth brep) that leaves the coorect geometry inside the cutter shape, but without cap, so I can’t do any srf afterwords.

I tried all the other split/trim for brep but without success. Any suggestion? (1021.2 KB)

Thank you

Moved to Grasshopper category

Is this what you are after? (1019.3 KB)

Thank u, it’s working…
Now I need to understand better why :smiley: