If you have vmware power cli installed try the below command to list the dvport group in dvswitch,
if you have multiple dv switch and pull the portgroup information of particular dv switch try the below.
#connect-viserver (vcservername)
#get-virtualswitch -name (name of dvs switch) | get-virtualportgroup
if you only on dv switch, use the below will list all the available port group.
#get-virtualportgroup