how to dynamically lookup datacenters through service catalog item

Issue

• I am trying to setup a service catalog item to provision a VM. I want to use the same dynamically generated lists that the Infrastructure -> virtual Machines -> LifeCycle -> Provision VMs uses for Data Center and Cluster selection. Screen shot included in 'cloduforms_vm_provisioning_screenshot.png' I created a custom service dialog and was trying to create elements that mimicked what is shown in the 'Sample RedHat VM Provisioning Dialog', but I couldn't determine what the entry Points would be for the methods listed. Screen Shot included in 'custom_service_dialog.png'