File Sync rule, like most other rules except Add-Devices rule, has been supporting filter functions in a different way many many years earlier than the introduction of filter for profiles.  So, it is possible with the MobiControl version you are using.

Just add a virtual device group (or even  a tree of virtual device-groups) with filter option(s) selected.  The filter criterion supported are more or less similar to those for profiles. Then assign your rule target to include the virtual group.  It should be noted that depending on the filter criterion chosen and whether intended devices are online or not, it takes time for server to automatically add devices  incrementally into the virtual device-group (or virtual device-group tree).  So, don't be surprised if you don't see all the devices you think to be fulfilling the filter criterion but not yet added to the virtual device group.

Hello Moine,

Did you get a chance to test the solution provided by Raymond on the post above?

Thanks

Thanks , it worked well :)