The D flat dominant flat ninth chord is a 5-note chord consisting of the notes Db, F, Ab, Cb and Ebb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Db7b9.
Interactive piano diagram for the D flat dominant flat ninth chord
Chords that are a subset of Db7b9. These contain less notes but all of them are included in Db7b9.