What is true of it
A♭m7♭5 is A♭, C♭, E♭♭ and G♭ — 1, b3, b5 and b7 counted from A♭.
E♭♭ is a double flat, and it has to be: every letter from A♭ upwards is used once, so the b5 cannot be written any other way.
These are also the notes of Bm6/A♭. Which name is right depends on what is underneath and what came before — the notes alone do not decide.
The easiest of the 1 fingering below is 1222: 4 fingers, held at the 1st fret.
None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.
Where its notes are on the neck
The brass dots are A♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
A♭m7♭5/C♭
4645
A♭m7♭5/E♭♭
7879
A♭m7♭5/G♭
bbab
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.