The B major seventh sharp eleventh chord is a 5-note chord consisting of the notes B, D#, F#, A# and E#.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Bmaj#4.
Chords that are a superset of Bmaj#4. The chords include more notes but always B, D#, F#, A# and E#.
Chords that are a subset of Bmaj#4. These contain less notes but all of them are included in Bmaj#4.
In case you prefer a non-interactive variant of the chord chart, we've embedded a PNG image below that shows the notes for the the Bmaj#4 chord. Feel free to save or share the image as needed.