piano chord
B♭m7♭5
B♭1D♭♭3F♭♭5A♭♭7
A diminished triad with a minor seventh rather than a diminished one — half diminished, and not the same chord as dim7.
Written the other way round it is A♯m7♭5 — the same twelve keys on a piano, a different piece of notation.
What is true of it
B♭m7♭5 is B♭, D♭, F♭ and A♭ — 1, b3, b5 and b7 counted from B♭.
These are also the notes of D♭m6/B♭ and C♯m6/B♭. Which name is right depends on what is underneath and what came before — the notes alone do not decide.