Worked on little Santa Monica blvd in the early 90's. Saw more than enough Iranians and Saudi's , very into gold jewelry at that time, driving big buck benz's along Wilshire & Redeo. Also Jewish, so pretty much middle eastern influence. A few token blacks, though mostly very hot black women...usually some rich white man's current toy. Jewish men seem attracted to black or Asian women...I know I am and I'm not Jewish. The rich from Japan were there, put keeping a low profile..their nature I guess.
Never watch BH90210, so know nothing about the show. Beverly Hills is not totally rich. Some middle class, to lower class, living there. That zip code 90210 is highly valued by some people and will pay extra on rent, or a lease, even if the can't afford it, just to have that zip #.
I live with my uncles, above Melrose, at that time. Took a few weekend jobs there about 10 years ago, so BH's may have changed a bit..but I doubt it.