Thanks @BillM223.
I just looked up "2024 FTB Publication 1001 Supplemental Guidelines to California Adjustments", and I found the following. It seems that only the dividends from U.S. obligations can be exempt from California tax.
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California does not tax dividends paid by a fund attributable to interest received from U.S. obligations or California state or municipal obligations if at least 50% of the fund’s assets would be exempt from California tax when held by an individual.
If the value of U.S. and California state or municipal obligations is at least 50% of the fund’s total assets, enter the amount of exempt interest dividends that are attributed to U.S. obligations included in federal income on Schedule CA (540), Part I or Schedule CA (540NR), Part II, Section A, line 2, column B.
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