To add Roommates, Co-Tenants and/or Dependents you go to the Lease in question and go to the TENANTS area. Here you will + ADD a Tenant.
When you enter the Tenant information you will see a box called ROLE. Here you can enter if this is a DEPENDENT or a CO-TENANT (For legal purposes).
NOTE:
If this is an EXISTING Lease then you will need to Edit the lease.
To Edit the lease go to Lease in Question > Views > Lease Terms > Current
After go to VERSIONING > Edit Draft
Now you can add new Tenants and/or Roommates