For "artist" and "genre" field that have separate multi-value field "artists" and "genres", it can be done in a single playlist with the following two rules:
(When searching for tracks that has only "Pop" in genre field)
Genre / match RegEx/i / ^pop$
Genres / does not contain / ;
But for other multi-value fields, it requires an additional playlist to exclude.
Playlist A:
Mood / match RegEx/i / ^easy$
Playlist / is not / Playlist B
Playlist B:
Mood / match RegEx/i / ^(?!easy$).*