I rarely think about Eagles music in terms of scales, but there are elements of harmonic G minor (D major chord), natural minor (F major chord) and G dorian (C major chord) in Witchy Woman. Or we could say that the verse uses the jazz minor scale, because it contains a majr 6th and major 7th (even when descending). But I'm sure Bernie wasn't thinking about scales.
Bernie plays a Gm6 in the verses on the acoustic. A minor 6th is sometimes used as the final chord in minor key songs in Finnish "schlager music". I'm sure Bernie just loved the sound of the chord in that context and didn't worry about scales.