Typically UHNW has a private family office, something between a concierge and philanthropy and a private investment organization, which maintain relationships with private banking services provided by Credit Suisse, UBS, etc. It can cost 1-2 million USD a year to run a private family office.
You never hear about family offices and in some areas you may only see a discreet sign at a posh building saying "private banking" and all of these folks want to keep it that way. The branding play here is being tight-lipped and discrete.