Can you post the code you're using for grouping as well as the content of the relevant tags for the file? There's bound to be a workaround.
The simplest solution is to use something other than parentheses, brackets or braces to bookend tag contents for display.
Thanks BenB. Well, this is my grouping:
$if($and($and($greater($len(%BAND%),1),$not($strcmp(%BAND%,%artist%))),$not($and($greater($len(%album artist%),1),$not($strcmp(%album artist%,%artist%))))),%album artist% - >>'['%date%[-%INDEX%]']'<< $replace($replace($replace($replace($replace($replace(%album%,'(','>>('),')',')<<'),'[','>>['),']','<<]'),'{','>>{'),'}','<<]'),$replace($replace($replace($replace($replace($replace(%album artist%,'(','>>('),')',')<<'),'[','>>['),']','<<]'),'{','>>{'),'}','<<]') - >>'['%date%[-%INDEX%]']'<< $replace($replace($replace($replace($replace($replace(%album%,'(','>>('),')',')<<'),'[','>>['),']','<<]'),'{','>>{'),'}','<<]'))
The if statement at the beginning is checking whether it's either various artists or a single-artist album which nevertheless has different track artists.
The main stuff goes on after that - I have
ALBUMARTIST - [YYYY] - ALBUMTITLE
as my basic pattern.
One of the albums which are problematic is this one:
Artist Name : sunn O)))
Track Title : «multiple values» Sin Nanna; It Took The Night To Believe; Cursed Realms (Of The Winterdemons); Orthodox Caveman; CandleGoat; Cry For The Weeper; Báthory Erzsébet
Album Title : Black One
Date : 2007
It should display as:
sunn O))) - [2007] Black One
but instead of course the brackets gradually fade out, and then neither the square bracketed year nor album title are visible at all.
For "normal" albums the workaround for the grouping ensures that the square brackets are not dimmed and so everything just looks normal.