From where the Craft(Work Skills) of Resource will be syncing to Resource in OFSC?

Summary:

As my understanding after Admin Sync in OIC, mobile store rooms and truck resources got integrated into OFSC Buckets and From Employee Sync the resources got directly synced to OFSC.

Content (required):

Here My Question is How the craft(Work Skills) will be applied to Employees like Electrical Fitter, Mechanic and Technical officer in Treatment operations.

In the Resource usage plugin while filling in the timesheet details it is asking me to choose the craft but the field user doesn't have that much idea which craft is assigned to them in ofsc.

Can anyone please help me to solve this issue?