Employees able to order on behalf of others

Hi all,

We have two ITShop structures (shopping centres):
  In the first structure all shelves have a owner, and approval policy "shelf owner".
  In the second structure there is several shops and shelves with different approval policies, but most are a combination of Manager and/or Product Owner. All products (service items) in this structure have a product owner.

In addition we have One Identity Manager application roles with permission groups for different service desks.

Our goal is to achieve the following:

- Shelf Owners should be able to see who have ordered products in their shelf, and be able to revoke these orders.
- Product Owners should be able to see who have ordered their products, and be able to revoke these orders.
- Managers should be able to place orders for their employees and be able to revoke.
- ServiceDesk shold be able to place orders in both structures for all employees and revoke these orders.

It is ok if Shelf Owners and Product Owners also are able to place orders, but this is not a necessisty.

I have been looking at the "Employees for whom a request can be placed" setting in Web Designer, but are struggling with the query. Is this the right parameter to edit or is there a better way to solve our goal?

We are using Identity Manager 8.1.1