(military) rank; level; grade

differential (between grades); salary differential

(math.) series

cascade; cascading

range of values; category defined by a range of values (tier, bracket, stratum etc)

super-; ultra-; hyper-

high level; high grade; advanced; high-ranking

higher authorities; superiors; CL:個|个[ge4]

first class; category A

top-notch; first-rate