Parsing inconsistent values across filenames?

I'm trying to get mp3tag to list song performers in individual tag panels. I've created the fields (PERFORMER_01, PERFORMER_02, etc.), but different files have different numbers of performers, so I'm struggling to tell "Filename - Tag" how to read the filename structure.

EXAMPLES:
(Performer 1, Performer 2, Performer 3,...) _ (Artist) _ (Album) _ (Track #) _ (Track Title)
Jack White, Meg White _ White Stripes, The _ Elephant _ 01 _ Seven Nation Army.mp3

Bon Scott, Angus Young, Malcom Young, Cliff Williams, Phil Rudd _ ACDC _ Powerage _ 04 _ Riff Raff.mp3

Notice the different number of band members between these tracks. I'm stumped as to how to tell mp3tag to fill in each "Performer" tag -- one per comma -- and move onto the "Artist" tag when it hits " _ " in the filename.

You are asking for a solution where different numbers of comma separated performers would be filled into the corresponding field names, right?

For your example something like this?
(Just to understand your question)

Yes - This is exactly what I'm looking for.

But what if the song has less than 5 performers?

Would it be helpful to first get 1 x
MY_PERFORMERS
field from Convert Filename -> Tag with
%MY_PERFORMERS% _ %ARTIST% _ %ALBUM% _ %TRACK% _ %TITLE%
and fill it with ALL your performers separated by a comma like this:


and with the Quick-Action "Split field by separator"

you could split MY_PERFORMERS into
several MY_PERFORMERS like this:

Or do you really need different numbered field names for different artist names?

They way you've done it is probably preferable. Thank you.