Lumber has the right of it. At the risk of a tangent, QR&O 107.02 lays out Authority to Lay Charges. Specifically, the following people can lay a charge:
a. a Commanding Officer (CO)
b. an officer or NCM authorized by a Commanding Officer to lay charges
c. a member of the Military Police assigned to investigative duties with the Canadian Forces National Investigation Service.
The authority for those in a unit other than the CO, therefore, comes from the CO. Commanding Officers will rarely, however, actually lay a charge as they could likely be the Presiding Officer for the trial. COs will appoint in writing who has the authority to lay a charge. I have seen some give the authority widely while others hold it more tightly. A unit would typically assign the RSM, DCO equivalent, DSM/TQSM equivalent, sub-unit OCs and CSMs/SSMs at a minimum. In a big unit or training institution I would expect to see the list get longer (Captains, WOs and Sgts depending). Ultimately, the CO will decide based on the expert advice of his RSM and other members of the " short hallway."
As an OC or Regimental 2IC I generally stayed clear of the charging process. My SSM would conduct the investigation and consult if required with the JAG - he would keep me in the loop in that I knew that an investigation was ongoing but I would be kept in the dark regarding the details. This would allow me to the hear the trial without predjudice.
Bottom line, your unit should publish a letter signed by the CO designating who can lay charges and everyone should know. A good place for this is Routine Orders.
Cheers,