Root on A string
x5657x
D7♭5 is the D dominant 7 flat 5 chord. Its notes are D, F♯, A♭ and C. A four-note altered dominant. Mute both outer strings.
x5657x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every D, F♯, A♭ and C on the first 12 frets. The filled dots are the root, D. Build your own shape from any nearby group.
Other D chords
Other dominant 7 flat 5 chords