Hero's Points.
I Don’t Main, 100% Alt
I think you’ll need to use hero points to unlock your new specialization’s circles. :o
Unlike beta, you won’t simply be given your elite specialization with HoT. That’s what the points are meant to be used for.
To counteract the extra points they gave for leveling, they’ll supposedly add something else you can buy. (sounds like a bad idea to waste a very limited currency)