Let's assume you have a song with the title ABBA - Waterloo and ABBA as artist.
You could use the Convert Tag -> Tag (ALT + 5 ) and this format string: $repl(%TITLE%,%artist% - ,)
This only works, if your existing content in the artist tag is exactly the same as the content before the - in the title.
If you really want to rename your track (= the filename) please follow @ohrenkino's advice.