Selecting only the surfaces parallel to the XY plane

Hello everyone,
I’m trying to explode a brep in grasshopper and then select the surfaces parallel to the XY plane, and get rid of the other ones. I think this might be easy but I couldn’t figure out yet, being new to grashopper

As an example, I wanna start from this

and go to this

thanks! (13.0 KB)

1 Like

Thank You Very Much Joseph! It’s perfect

I dont know why, but it doesn’t work with some parts. Take a look on these ones.
Do you know why?

Geometry attached
trouble parts.3dm (371.1 KB)

Replacing Equals with Smaller (‘B’ input = 0.01) fixes the problem. (33.1 KB)

Thank you again!