Is that the LLC is facially some sort of consulting, management, or campaign service company that is paid for "services" rendered to the campaign.
The LLC revenue goes to family and friends of the candidate for the "services" they provided through the LLC.
If he is an employee, director or officer of the company, then income from the company would show up on his financial disclosures. So, the better route is for him to have a different company which is a contractor to the LLC, and he gets paid by that second company for consulting, speaking fees, or whatnot.
For example, he pays $X to Able Co., a campaign management company. Able Co. arranges an event, and pays Baker Co. $Y to book the candidate as a paid speaker at the event. On his financial disclosure, the incoming from Baker Co. shows up as speaking fees, and in his campaign disclosures the payment to Able Co. shows up as a campaign expense - but those two transactions are not connected in any public disclosure, because Able Co. doesn't have to account to the public on where its money went.