The Position function "Format Date for Position to Job Requisition Mapping" is not available when configuring Requisition Field Mapping business rule with the same scenario.
The rule function is available only if you use the OData based internal Position to RCM integration.
Disable the SFAPI based integration in Recruiting section in Provisioning and enable OData based integration. Follow Position Management implementation handbook for more details.
Integration , KBA , LOD-SF-EC-POS , Position Management , LOD-SF-EC , Employee Central , LOD-SF-EC-INT , Manage Pending Hires (Integration RCM/ ONB/ OBX + UI) , Problem