Cal. Welf. and Inst. Code § 304
After a petition has been filed pursuant to Section 311, and until the time that the petition is dismissed or dependency is terminated, no other division of any superior court may hear proceedings pursuant to Part 2 (commencing with Section 3020) of Division 8 of the Family Code regarding the custody of the child or proceedings under Part 2 (commencing with Section 1500) of Division 4 of the Probate Code, except as otherwise authorized in this code, regarding the establishment of a guardianship for the child. While the child is under the jurisdiction of the juvenile court all issues regarding his or her custody shall be heard by the juvenile court. In deciding issues between the parents or between a parent and a guardian regarding custody of a child who has been adjudicated a dependent of the juvenile court, the juvenile court may review any records that would be available to the domestic relations division of a superior court hearing that matter. The juvenile court, on its own motion, may issue an order as provided for in Section 213.5, or as described in Section 6218 of the Family Code. The Judicial Council shall adopt forms for these restraining orders. These form orders shall not be confidential and shall be enforceable in the same manner as any other order issued pursuant to Division 10 (commencing with Section 6200) of the Family Code.
This section shall not be construed to divest the domestic relations division of a superior court from hearing any issues regarding the custody of a child when that child is no longer a dependent of the juvenile court.
Ca. Welf. and Inst. Code § 304