(a) A member’s ex-spouse who is receiving or is entitled to receive payments from the system, including a portion of the surviving spouse’s allowance, pursuant to an order of the court dividing the community property interest in the member’s retirement allowance may designate one or more beneficiaries who shall receive those payments following the death of the ex-spouse. If there is no designated beneficiary, payment shall be made to the estate of the ex-spouse. Those payments shall terminate upon the death of the member or the surviving spouse.
(b) This section shall not be operative in any county until the board of supervisors, by resolution, makes this section applicable in the county.