The G sharp major seventh chord is a 4-note chord consisting of the notes G#, B#, D# and F##.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as G#maj7.
Chords that are a superset of G#maj7. The chords include more notes but always G#, B#, D# and F##.
Chords that are a subset of G#maj7. These contain less notes but all of them are included in G#maj7.
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 G#maj7 chord. Feel free to save or share the image as needed.