If a chord you’re trying to find begins with a sharp or flat note, you’ll find them both sharing the same wedge of our circle of fifths.
For example, if you were looking for the F# major chord, you’d tap the “F# / Gb” button:
And if you were looking for Gb, you’d tap the same button.
When a note has a sharp or a flat in it, we’re essentially giving that note a name based on what’s next to it.
So, when we say “F#”, what we’re actually saying is “take the note F, and move it up by a half step”:
But it can work the other way, too.
Imagine you were trying to describe that note on the keyboard. You could just as well say “take the note G, and move it down by a half step”:
Which is exactly what’s going on with Gb.
And, as you can see, it points to the same note.
Two names, same note.