Open Stack

Scenario:
-DomainA (TenantA, TenantB)
-TenantA(userA)
-TenantB(userB)
- A template which start OS:NOVA:SERVERS

1. Is it possible two run simultaneously the same openstack stack
create command?
2.
a. how can i specify that i want, in the first case, the VMs of the
stack, beloging to TenantA
and in the second case to TenantB
b. for the OS::NOVA::SERVER as fas as i can see there is no such
property to Distinguish project names

c. I want to achieve something like this
openstack stack create "mystack" for TenantA
openstack stack create "mystack" for TenantB
 openstack server list for TenantA
            VM1 RUNNING
            VM2 RUNNING
            ....
openstack server list for TenantB
            VM1 RUNNING
            VM2 RUNNING
            ....

So THE SAME VMs for both Tenants!

3. In the end, how is multi-tenancy achieved?
So far, I have achieved it, by having two different stack names,
tenantA and tenantB correspondingly, which take as input the same template,
with the same parameters.