Hi @Neal Fridrich,
You'll want to consult with your managing broker as to what they allow and how they require it to be documented, as I know that most in my area do not allow it despite it being legal with the state.
Generally speaking you'll need to document two things: 1) agency relationship(s), and 2) compensation.
Re agency relationship(s):
You would sign an agency agreement with a) one of the parties (seller, or end-buyer), b) both of the parties with dual agency disclosure language, or c) or notice of no agency disclosures with both parties, based on whichever is most appropriate and true to the circumstances.
Re compensation:
A compensation agreement will be needed in conjunction with one of the above agreements. Either a listing agreement with compensation, a buyer agency agreement with compensation, or compensation on either or both of the notice of no agency disclosures.
Essentially the wholesale fee becomes a commission and then is handled as such at the brokerage level. But again, check with your broker.