Where is remove duplicate tracks

[nominalgrevious]

Just installed v 5.622 fresh, scanned external hard drive that has nearly all my music and computer's internal hard drive that has some of the music backed up. Now there are two copies of most of the files in the library.

Surely there is some "eliminate duplicated tracks from library" option that is for some reason buried. Where is it?

Eliminating duplicates from a playlist would also be fine, but I can't find that either.