Limit Relationship Choices based on another field..

I did this, but I wanted to further limit the selection.   So I ended up going with a new form and showing that form on Grid Edit.  It worked.  But then, when the user hits edit on the parent.  It didn't work....

So I went back to the a conditional filter and created a formula in both to basically result in a combo of project number and "_1" if I wanted it shown, and then matched that in the other table.   And it works like a charm now.