I want to see what files have duplicate fields prior to using the remove duplicate fields action. I searched but couldn't find any answers. Is it possible?
Maybe, if you can reduce the amount of tag-fields to check for being a meta-tag-field to a manageable number.
For one tag-field you can use the Filter with this expression ..."$if($neql($meta(TAGFIELDNAME,1),),1,0)" IS 1
... or ..."$if($eql($meta(TAGFIELDNAME,1),),0,1)" IS 1
... or ..."$iflonger($meta(TAGFIELDNAME,1),0,1,0)" IS 1
You can combine more of such expressions by using the filter operand OR ...
(expr1) OR (expr2) OR (expr3)
Sure, it would be more simple to do, if the Filter would support a syntax like ...
%_tag% HAS META
%GENRE% HAS META