Good day.
There is more than one option for copying the process client from the process product subfield. You can try, in order not to deviate far from your logic, change the fields you use (so as not to copy fields of the "Contact Directory" type) - add the product field of the process and the process of the Integer type, and do the following three actions -
https://i .imgur.com/c16FKv7.png - copy the Contact Directory subfield into the Integer type subfield (so the system will extract the client ID), then transfer it to the process field, and fill the Client field from it.
Such an example solution should work.