You can create a role under a project/assignment (or use an existing, unassigned role) in order to make a preliminary or definitive booking for a subcontractors in the same way that you book your own employees.
On the matching page, make sure that you select the tab "Subcontractors" to list all subcontractors.
Want to learn more?
- Read more about role matching here
- Learn how to use the Timeline in order to get an overview of which assignments your subcontractors are booked on here