Cal. Civil Code § 8446

A claimant may record one claim of lien on two or more works of improvement, subject to the following conditions: (a) The works of improvement have or are reputed to have the same owner, or the work was contracted for by the same person for the works of improvement whether or not they have the same owner. (b) The claimant in the claim of lien designates the amount due for each work of improvement. If the claimant contracted for a lump sum payment for work provided for the works of improvement and the contract does not segregate the amount due for each work of improvement separately, the claimant may estimate an equitable distribution of the amount due for each work of improvement based on the proportionate amount of work provided for each. If the claimant does not designate the amount due for each work of improvement, the lien is subordinate to other liens. (c) If there is a single structure on real property of different owners, the claimant need not segregate the proportion of work provided for the portion of the structure situated on real property of each owner. In the lien enforcement action the court may, if it determines it equitable to do so, designate an equitable distribution of the lien among the real property of the owners. (d) The lien does not extend beyond the amount designated as against other creditors having liens, by judgment, mortgage, or otherwise, on either the works of improvement or the real property on which the works of improvement are situated.