directories for different audio formats

I’m new to volumino, works fine to me.
Up to now, all my files are sorted in directories “usb hd/artist/album”
File types are: mp3, flac, mp4
some albums are ripped to mp3 AND flac, so there are dublicate songs in each album directory.

Coming from foobar, this was not a problem - you can sort the codec type in the track list within foobar.
But now, in volumino, I see every file twice without a chance to sort for flac or mp3 (or did I miss this?)

How do you handle this? different directories for mp3 and flac - which is not a really good idea for me, with a structure artist/album?
any other way to handle?
thanx, uwe