How to limit what a Purchaser can see in the Sourcing Cockpit

We have a requirement where we would like to limit/restrict the unsourced items a purchase can see and action fron the Sourcing Cockpit base on the following criteria:

1. Company Code

2. Plant

3. Purchasing Group

Ideally we would like the systm to use/reference the Purchaser assigned attributes in the org structure to determine the Company Codes, Plants & Purchasing Groups he is responsible for.

How can we achieve this?