Filter with Scripting
Check if a field is longer than 4 characters:
"$len(%bpm%)" GREATER 4
Files with multipe artist tags:
"$meta_sep(Artist,\\)" HAS \\
Check if two fields have the same value:
"$if($eql(%artist%,%albumartist%),yes,no)" IS yes
Check if the title is part of the filename:
"$ifgreater($strstr(%_filename%,%title%),0,yes,no)" IS yes