Reference rhino closed polysurface in grasshopper

I’m trying to use a bounding box to lay over a pattern on a shape from rhino, but ‘surface’ isn’t accepting/recognizing it. Does anyone have ideas on what to do? (30.0 KB)
Shape.3dm (6.8 MB)
The file and the grasshopper definition I’m working with

Not exactly sure what the expected result is… (20.1 KB)

I’m trying to make the polysurface look like a net. Can you explain how you made it recongizable to grasshopper?