6.2First destination: A♭ major

Look at:

B♭m7 → E♭7 → A♭maj7

That is:

ii → V → I

in A♭ major.

So the first important thing to hear is not:

Fm7, B♭m7, E♭7, A♭maj7

as four unrelated chords.

Hear:

Fm7 leads into a ii–V–I in A♭.