Field - "USE" - To have only Template or Position

Summary

Requisition Field "USE" to have only Template or Position to select

Content

Our client is on Position Management and we are looking for an option to mandate Template/ Position creation process before Requisition Creation.
Till 18C, we were able to make template field in Requisition creation page as mandatory and with that we were able to handle the above requirement, but in 19A with the new field "USE" we are not able to mark the selection of template as mandatory.
So we are looking for options to remove other available drop down values from the field - USE

Form 19B when we get position management in ORC, we would require to mark the selection of Position in this field mandatory, so we can streamline the process of having position created first and then that needs to be used for Requisition creation.