For deposits, you need info on who is benefitting which would be the actual customer(s) who own the account. This would be the business for a business account and all owners of a joint account. You do not include the signers of a business account on the CTR.
The conductor may not be benefitting from the transaction, especially on a business deposit, but you still need that conductor info for that section of the CTR.
For withdrawals, the beneficiary is usually the person conducting the transaction, but you may want to ask in certain situations.
I've just writed a wrong.