Legal Question in Business Law in California

I'm not clear on what you mean by "finder." Do you mean a person who locates ("finds") the debtor for the creditor, like a private detective? Or possibly you mean a person who "finds" debt that an investor/speculator can buy from creditors for 50c on the dollar? Or a person who "finds" the debtor's hidden assets so the creditor can levy on them?

In any case, I don't know of any percentage limit that the creditor may pay a finder working for him.

However, if you are asking about money that can be tacked on to what a debtor has to pay, I'd say the "finder" cannot receive anything at all from the debtor.

Please explain what you have in mind, then we can look for an applicable statute.