I assume in that scenario Public is the share and Music a folder within it, but I've never used that syntax and it appears that WiiM doesn't support it.Wonderful. Thank you so much. But this goes against the example of \\MyNas\Public\Music
I'm surprised you're still asking about it; haven't you tried it yet?

If you want to use the WHA for browsing then use Plex, otherwise use Symfonium with any compatible server (including Emby).