Expression Question

I have this expression (below) that I need to pull from my Session(s) column text contained in the search or part of the text contained in the search.
So if I search for strings “S1” or “S2” it returns rows that contain either of those searches but only that exact string. I also need that to return rows containing strings “S1, S2”.

Right now it will only return strings that contain “S1” or “S2” not “S1, S2”. Any help is appreciated.

This appears to be a duplicate post.