Make a part of a static mesh invisible

In a blueprint I have 2 planes. One is obstructing the other. I want to make a progress bar by moving the obstruction plane and revealing the other plane.This would be alright but the mesh isn’t big enough to hold the obstruction plane. How can I hide a part of the obstruction plane after it leaves the mesh.


I had to do the same kind of effect but with desintegration, I followed this tutorial, if it can help