i have a question . when we do bivariate fit by group in JMP and click on the row legend, it can hide unselected. is it possible if it can also hide fit lines?
that would really help in comparing two factors with many lines on the chart.
Another option would be to select from the red triangle Script>Automatic Recalc and then again from the red triangle Script>Local data filter and select your grouping column for the filter. Now you are set up to filter out the groups you don't want to see. The advantage here is that you can easily look at a variety of groups without having to hide and exclude and update, etc.
I like your approach, which (Local data filter) works for time being.
But i think JMP should treat applying same rules( to fit lines as to markers when you click on one of legend).