Every fingering that fits a hand
6704
easy
6434
hard
643x
easy
6797
hard
What is true of it
D♭dim is D♭, F♭ and A♭♭ — 1, b3 and b5 counted from D♭.
A♭♭ is a double flat, and it has to be: every letter from D♭ upwards is used once, so the b5 cannot be written any other way.
The easiest of the 4 fingerings below is 6704: 3 fingers, held at the 4th 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 D♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
D♭dim/F♭
x434
D♭dim/A♭♭
010x
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.