Root on A string
no fifthx-14-13-14-13-x
B7♭9 is the B dominant 7 flat 9 chord. Its notes are B, D♯, F♯, A and C. A compact four-finger grip without the fifth. Try it as V in a minor key.
x-14-13-14-13-x
Numbers show frets from the low E string to the high e string; x means don't play that string.
Every B, D♯, F♯, A and C on the first 12 frets. The filled dots are the root, B. Build your own shape from any nearby group.
Other B chords
Other dominant 7 flat 9 chords