Alex tried explaining this to me and my brain stopped working so I drew it in MS Paint and now I understand. I'll share with the class in case it helps anyone else.
Yes, HLS is refuelled by the same depot, twice, in two different orbits...
So... Depot launches to LEO, gets refilled by Tankers in LEO, then HLS launches to LEO, gets refilled in LEO by Depot, then heads to a higher orbit. Depot then gets refilled again and also heads to the higher orbit. Then HLS gets refilled again.
How is this "6 to 8" flights?