Trim a trimmed surface

Dear my friends
I have a trimmed surface. (Surface 1)
now I want to trim it with a curve (like Surface 2)
please tell me how can i do it?
Trim a trimmed (6.3 KB)

Try the Component Boundary Surfaces, use both the Surface 1 and the Curve as input, should work!

Thank you for your reply.
I dont want to create a surface with boundary!
I want to trim surface 1 with a curve

Use Surface Split and List item afterwards to select one of the resulting surfaces.