so Dif along... is August - July.  I figured that out.  topx is the rank(dif) down the client code description.  Now I want to filter out only the rows where topx <= 10.  How do I do that.  For what it's worth, this is also very difficult to do in DAX.

By the way, you can't just put topx in to the filter directly because then there will be no data for July since the July data has to topx value at all.