Divide the lines by the surface

Hello all
I’m trying to divide the lines by the surface into two parts.
Actually, I want to get the all lines above the surface.
I don’t konw if there is some tools can do it.
Thanks in advance.

Divide the lines.gh (5.9 KB)


syachcho-help divide the line.gh (7.5 KB)


Divide the lines_re.gh (9.2 KB)