Generating display element

Help with Element on My App
Ok on my app I have It where when “selected featured artists search box “ go to repeating group featured artists and “selected primary artists searchbox” go to repeating group primary .

I want to have a field " display artist " generated Primary Artists Feat. Featured Artist when theres a featured artist but when there’s no featured artist to remove " Feat." and only to display Primary Artist . To ensure it go tod display artist field in data as well as on that page .