Purchase requisition for material group and value

Dear colleagues,

Our business has requirement to initiate procurement with PR. In purchase requisition, they will write a value of requirement, but not the exact material or quantity, because in that moment they do not know what would be exact material (unit of measure, quantity…) they know just value limit and which material group is it. Such PR will be used for RFQ process (which is outside SAP), when contract is signed it needs to be linked to PR, but in contract we will have particular materials.

Is it somehow possible to achieve this in SAP ERP?

Best regards,

Harry