That's already possible. You could use the tag 'Grouping' for example:
Thank you so much! After using Musicbee for a year I still find myself discovering new features that were already there, hidden. Would you know if you can have a manual order, instead of alphabetic? Would be nice to have studio albums up top, followed by other groups. Edit: Fixed it by sorting descending instead of ascending. Another question though, sorry. Can the font size for the grouping be changed? Can't seem to find it.