But if you want to keep it simple (like me), you can use a custom search on the semi-colon but you have to search the <Artists: Artist> field:
I'm yet to test the above, but looking at it by itself:
Will it pick up every scenario? For example, a track tagged with:
<Artists: Artist> being Artist1
and
<Artists: Guest Artist> being Artist2
If it's only looking at <Artists: Artist>, can it know that there's a 2nd (guest) artist in the file?
I already spend hours on end on social media. Might as well spare a few of those to a greater purpose here.