The A flat minor seventh chord is a 4-note chord consisting of the notes Ab, Cb, Eb and Gb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Abm7.
Chords that are a superset of Abm7. The chords include more notes but always Ab, Cb, Eb and Gb.
Chords that are a subset of Abm7. These contain less notes but all of them are included in Abm7.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Abm7 chord. Feel free to save or share the image as needed.