I can offer you 3 possible solution for this Problem..
Create a line on the Top plane and use extrude Surface in a way that the surface interscts all the existing surfaces.
Later use the newly created Surface under 'Surface trim' Feature to ged rid of any Surface on the right.
Select the plane (showed in your photo) and use 'split' Feature to split every Surface on the left and right side of the plane
If you dont Need the surfaces on right side of the plane, use 'cut with surface' Feature and select the plane. It will delete everything on the right/left side of that plane.
Thank you for your time, found a way myself too. Was about to delete the question, but I can't apparently.