Those entries probably come from the NAS' DLNA server. Are you browsing or using it as a zone under MC's Playing Now.
I don't thing the standard import methods for MC will pull in such values, and think they'd only appear if you were using MC as a DLNA controller for the NAS' DLNA server (via Playing Now > <NAS zone>). Or you built up a library from that Zone.
...and sadly, this is where I've gotten in over my head (fairly new to MC). It's not clear to me what the difference between browsing and a zone is, or how it appears. (And I'm not at my PC now to send a screen shot). I set up the NAS as a Library and use MC to choose the media I want to play and direct it to the player (sometimes the local MC player and sometimes a SONOS unit or a Naim amplifier in the living room).
My library does not show up as a zone under playing now...if that is what you mean. Only my "output devices" show up: MC player, a Naim amp, and some SONOS units...and these all work fine, and some video equipment that I use to send video to the TV.
So, in MC, my NAS library is selected and I navigate the tree on the left hand side to choose one of the canned views to find an album or artist, then move to the right side display (panel?) to choose an album or song to play and play it.
Apologies for being the "ignorant user" here...there is a lot to MC and I'm still in the early part of the learning curve.