how to make item purchasable for sepecific responsibility and internal orderable for another respons

We have a requirement to customize iprocurement to allow certain users to order specific item from the store using IR Only. but they should not raise PR for the same item.

another users should be able to raise PR only for the same Item but they should not be able to raise IR.

both set of users are in the same organization.

I tried to play with item attribute in the Inventory Item master. but no luck.

please, advise how to do that