Filter comparing two fields

How do you filter to select songs where two tags are equal.

I've tried
$eql(%artist%, %artist_bak%)
$neql(%artist%, %artist_bak%)
%artist% EQUAL %artist_bak%
$eql(%artist%, %artist_bak%) IS TRUE

None give the expected behaviour.

This simply states that the fields are equal (sort of).
You are missing the "if":
"$if($eql(%artist%,%artist_bak%),1,0)" IS 1

Thanks - I tried this expression, but it does nothing in the filter. Whether I set it to "IS 1" or "IS 0", I still see all 25 files.

DOH I missed the quotes.

WOrks a treat thanks!

What are you trying to do?

Yes, what are you trying to do?

Find song A and B and possible C, D, E... than happen to have the same title?

Or trying to find all of those files that have the exact same title written to them in two different fields- because for whatever reason you have titles stored in more than just one field?

I think that it is fairly clear:
The OP wants to compare the 2 fields %artist% and %artist_bak%.