This was likely suggested before, but many of the relationships I deal with are reciprocal/feedback/dialectical where the child of the parent in turn affects the parent, effectively becoming its parent's parent. Feedback relationships of this kind are crucial to modeling the world and should be possible in PB.
Gerard Coppejans commented
Sea my feature suggestions under #3375 and #3514
I'd love to know how and when this would be used
Karl Hebenstreit commented
This relationship seems to me to be a jump thought. You can think of a jump thought as going to another dimension (going into/behind the screen)