Cal. Civ. Proc. Code § 404

When civil actions sharing a common question of fact or law are pending in different courts, a petition for coordination may be submitted to the Chairperson of the Judicial Council, by the presiding judge of any such court, or by any party to one of the actions after obtaining permission from the presiding judge, or by all of the parties plaintiff or defendant in any such action. A petition for coordination, or a motion for permission to submit a petition, shall be supported by a declaration stating facts showing that the actions are complex, as defined by the Judicial Council and that the actions meet the standards specified in Section 404.1. On receipt of a petition for coordination, the Chairperson of the Judicial Council may assign a judge to determine whether the actions are complex, and if so, whether coordination of the actions is appropriate, or the Chairperson of the Judicial Council may authorize the presiding judge of a court to assign the matter to judicial officers of the court to make the determination in the same manner as assignments are made in other civil cases.