Legal Question in Real Estate Law in California

You cannot put a lien on a mortgage ever. You could possibly put a judgment lien on the underlying debt which might entitle you to the rights under the mortgage, but the concept of putting a lien on a mortgage just makes no legal sense.

A mortgage IS a lien on the mortgaged property.

Your one-sentence question makes no sense as written; I can only guess what may have happened. Possibly you used money borrowed from a home equity line of credit to pay off the balance on a mortgage (probably not a true mortgage, either; most likely a note secured by a deed of trust). If so, the mortgage lender should have reconveyed the deed of trust back to you, which essentially cancels the mortgage (deed of trust) when the reconveyance is recorded.

However, at the same time you were extinguishing one lien against the property - the mortgage - you were either creating or increasing the lien of the home equity line of credit, in other words, doing a sort of refinancing. The result is a new and different lien. Hopefully, the terms are better for you.

........if this is indeed what happened, and what you're asking about.