What is true of it
D♭dim7 is D♭, F♭, A♭♭ and C♭♭ — 1, b3, b5 and bb7 counted from D♭.
A♭♭ and C♭♭ are double flats, and they have to be: every letter from D♭ upwards is used once, so the b5 cannot be written any other way.
The easiest of the 1 fingering below is 6767: 3 fingers, one of them barring the 6th fret, held at the 6th 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♭dim7/F♭
9a9a
D♭dim7/A♭♭
0101
D♭dim7/C♭♭
3434
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.