Implementing sub-tenants for multitenancy

Hi Everyone,

we have below scenario where we have multiple tenants

Tenant1:
1) Admin user of a tenant creates one or more departments and sets up a owner for each department
2) Owner of each department group creates individual users

Tenant 2 …Tenant n has the same above rules.

Can someone help me how i can achieve this functionality using multi tenancy add-on or using access groups of cuba-security.

Thanks in advance for the help.