If you are interested in monitoring each volume on this drive separately, then you can monitor given virtual machine through WMI/SNMP (need to be managed as a node).
If you can't or don't want to monitor such VM through WMI/SNMP, then only option which comes to my mind is to have integration with Virtualization Manager. This will allow you to monitor summary space utilization by all volumes on a VM (for all virtual disks assigned to this VM). If you need to monitor virtual disks separately, you can try out Virtualization Manager by Solarwinds as well.
I'm assuming you want to monitor the actual logical volume in the Guest and not the VHD or VHDX file itself? If so, it's best to monitor those with SAM via WMI or SNMP.