Cut lines passing polyline


I guess this is an easy one.
I wonder if anyone here knows a quick way to draw a polyline along the facades then cut all lines outside of that one.
(also cut inside the “hole” in the middle)

This topic could interest you:

Please send a screenshot of your graph showing your specific issues.

In all honestly it looked far too complicated. I just want to cut a bunch of 2D lines by selecting the outer lines along the facade instead of cutting each single line manually.

I will also use this later on in Dynamo, projecting those lines on the roof surface.

This and other related posts will help to get started: