Green’s Dictionary of Slang

(Scot./Irish) members of the upper classes.

1973		(con. mid-1960s) J. Patrick Glasgow Gang Observed 233: Hob-nobs – rhyming slang for snobs.
1991		T. Delaney Where We Sported and Played 101: A row of chalets on the beach front, which the hobnobs of the city rented.