Cal. Civ. Proc. Code § 398

If, for any cause, specified in subdivisions 2, 3 and 4 of section 397, the court orders the transfer of an action or proceeding, it must be transferred to a court having jurisdiction of the subject matter of the action which the parties may agree upon, by stipulation in writing, or made in open court and entered in the minutes or docket; or, if they do not so agree, then to the nearest or most accessible court, where the like objection or cause for making the order does not exist.

If an action or proceeding is commenced in a court, other than one designated as a proper court for the trial thereof by the provisions of this title, and the same be ordered transferred for that reason, it must be transferred to any such proper court which the parties may agree upon by stipulation in writing, or made in open court and entered in the minutes or docket; if the parties do not so agree, then to any such proper court in the county in which the action or proceeding was commenced which the defendant may designate, or, if there be no such proper court in such county, to any such proper court, in a proper county, designated by the defendant; if the parties do not so agree, and the defendant does not so designate the court, as herein provided, or where the court orders the transfer of an action on its own motion as provided in this title, to such proper court as the court in which the action or proceeding is pending may determine.

The designation of the court by the defendant, herein provided for, may be made in the notice of motion for change of venue or in open court, entered in the minutes or docket, at the time the order for transfer is made.