Can OpenStack create different private virtual networks; where these networks consist of VMs that can be created from the virtual network from a resource pool assigned by the main service provider?

Scenario: Company_A buys a pool of resources from Host_Company for their virtual network. Company_A then wants to have the ability to use these resources to create the number and size of VMs as Company_A's admin chooses. Company_A wants their virtual network to be private from all other virtual networks being hosted by Host_Company, thus Company_B does not even know that Company_A exists or that it is being hosted by the same Host_Company.

Can such a structure be deployed by OpenStack with all the available OpenStack products?

Host Server : (One OpenStack deployment on vSphere managed hardware) =>

               -> Virtual Network A -> VM_A1
                                    -> VM_A2
                                    -> VM_A3
                                    -> VM_A...

               -> Virtual Network B -> VM_B1
                                    -> VM_B2
                                    -> VM_B3
                                    -> VM_B...