Find number of total discs from single discnumber

How would you go about extracting %TOTALDISCS% if you only have a %DISCNUMBER% in n format?

Some way to match the higher %discnumber% value from the selected files and apply it to %totaldiscs%.

Only manually. MP3tag does not compare values from different files.
Or use the auto numbering wizard Ctrl-K

Yeah, ctrl k is the way I would be looking at. Or tag sources, but that's probably not faster than manually doing it.

If not all the discs are present, then the auto number wizard probably wouldn't work. You could export the tag data though. Getting that data into a spreadsheet might make it easier to do this in bulk.

I would do it manually this way:

  1. Load all files
  2. Filter: discnumber PRESENT AND totaltracks MISSING
  3. Sort for discnumber - album descending
  4. Inspect visually to which album-files the highest discnumbers belong an write the highest discnumber shown of an album to totaldiscs in the tagpanel
  5. Periodically refresh the filter by adding a character and deleting it again