Root on A string
no fifthx-11-10-11-10-x
A♭7♭9 is the A♭ dominant 7 flat 9 chord. Its notes are A♭, C, E♭, G♭ and B♭♭. It is the same chord as G♯7♭9. A compact four-finger grip without the fifth. Try it as V in a minor key.
x-11-10-11-10-x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every A♭, C, E♭, G♭ and B♭♭ on the first 12 frets. The filled dots are the root, A♭. Build your own shape from any nearby group.
Other A♭ chords
Other dominant 7 flat 9 chords