Determine Business Group VM belongs to

There are multiple entities in vRA data model that the business group (aka provisioning group) can be determined from, such as Owner, VirtualMachineTemplate, etc. But when I try to get a link to the Business Group I always get an empty array.

Can you see anything wrong with the code below?

var model = "ManagementModelEntities.svc";

var entitySetName = "VirtualMachines";

var virtualMachines = vCACEntityManager.readModelEntitiesByCustomFilter(vcacHost.id, model, entitySetName, null, null);

 

for each (var vm in virtualMachines) {

     var owner = vm.getLink(vcacHost, "Owner");

     var provisioningGroup = owner[0].getLink(vcacHost, "ProvisioningGroup");

     System.log(provisioningGroup);

}