Second instance or alternative

[DetlevD]

@zerow

But this new filter would have to work in such a way: show only files with titles similar to titles of other files
And the key would be how much similar? ... Is it doable?

Once you have defined the rules for similarity, then it might be done with Mp3tag too.

Have a look there ...
Simple Soundex Calculator
I have coded a well known algorithm into Mp3tag Export Scripting Language.

DD.20150325.2030.CET