Cal. Prob. Code § 2406

If there is a dispute relating to the estate between the guardian or conservator and a third person, the guardian or conservator may enter into an agreement in writing with the third person to submit the dispute to arbitration under Title 9 (commencing with Section 1280) of Part 3 of the Code of Civil Procedure. The agreement is not effective unless it has first been approved by the court and a copy of the approved agreement is filed with the court.