Renaming all Disc 1/1 to 1

Hey all, new member here and sorry if this has been asked before. To try and support the clearest naming convention for Plex, I set up a rule in Mp3tag to rename most of my tracks with

%discnumber%$num(%track%,2) - %title%

however, many of my discs say "1/1" instead of just "1" which results in wonky naming. Is there a way to make mp3 tag look through every folder and rename the 1/1 or 1/2, etc with just the actual disc number? I suppose alternatively, if I could rename my files ignoring the "/1" or "/2" after the disc number, that would get me around the problem just as well.

Try
$num(%discnumber%,1)$num(%track%,2) - %title%