Have you looked at USC’s CS & Business and AI for Business programs? They are joint degrees between the Viterbi School of Engineering and the Marshall School of Business.
How interested are you in the business component and why are you interested in the joint degree? Admissions to the programs at USC are competitive. You would need to show that you know about the programs and do a good job articulating your reason for applying to them. Attending open houses, informative webinars, etc. prior to applying makes a difference at USC.
Within the UCs, a few offer undergrad business degrees. Berkeley and Riverside have had programs for several years. UC Davis opened their business school to undergraduates in 2025. Irvine offers a BA in business. Someone correct me if I am wrong, but I believe it is more difficult to double major or combine degrees across colleges at Irvine than it is at the other UCs.