User Interface Location: Click Model > Sketch.

In Creo 11.0 you can now trim self-intersecting composite curves in Sketcher. This provides additional flexibility to further modify a composite curve which was created using theProject orOffset tool. Previously, self-intersecting composite curves could not be trimmed. 

For example, in the image below, the upper curve self-intersects and was created by projecting the lower curve. The curve can now be trimmed, using a point of self-intersection to determine the segment to trim.

Increased productivity by removal of limitation​ when trimming composite curves that self-intersect.