I wrote an extension attribute that lists the inventory from a Windows VM, but a better, and more flexible, way to do it would be to add the "~/Applications (Parallels)" path to the inventory collection preferences in your JSS:
Settings -> Inventory Options -> Inventory Collection Preferences -> Manage Search Paths for Applications (on the Software tab beneath "Application Collection") -> Add Search Path for Mac OS X -> Enter "~/Applications (Parallels)/" in the box (without the quotation marks) and click Add Path, then Save. This will bring the Windows VM inventory into the application inventory of the computer record in the JSS and allow it to be leveraged in Smart Groups and Saved Searches.
