I'm not sure that Nosler or other ammo companies will divulge that information for a lot of various reasons. That being said when I had my 280 Remington I used IMR4350 with 140 gr. Partitions and the rifle liked that powder. I also had good luck with H4831SC. I never messed around with a bunch of different powders and when I find a load that works in my rifle I tend to stick with it.
H4350 would be another good one to try in your 280.
David is correct in his assessment that Nosler is not likely to inform the public of the powder used in their loads. Among other reasons is the likelihood that they are using non-canister powder for their loads.
Generally speaking, powders that are situated in the mid-range of the burn spectrum deliver excellent results. In my .280 Rem, I've found RL19 and H4831 to deliver excellent accuracy and velocity with the 140 grain AB.