I don't think there are specifics given but I'm sure Ainge has contacted the Charlotte GM or Jordan and said, something like would you be interested in moving back from 9 and if so what would it take.
The answer would probably be something like, Sully, 16, 28 and two future 1's.
Then they haggle back and forth and come to a conclusion of, if Sac is interested in moving down, Boston is interested in moving up, and Sully and 16 would do it.
Now on draft night, lets say WCS drops that far which isn't going to happen. Danny calls up Jordan or the GM and says, you still looking to move back? Sac says yes or no depending on who is available. Ainge says Sully and 16 like we talked about? Sac says, well WCS is here still so we need more than that now. Ainge says yes or no but that is how I am 99% sure it works.