if you want to filter VMs based on folders then I'd recommend that you use vm.folder.name and/or vm.folder.level-X attributes. Below is an example of Top-N widget:
1. Search query:
vm.powerstate:poweredon AND (vm.folder.name:"Folder 1" OR vm.folder.name:"Folder 2")
2. add requested attributes in Columns tab, i.e.
vm.cpuload.latest vm.consumedPercentMemload.latest vm.volSummary.freeSpacePercentage
Apply the same process if you want to get data into XLS format (via Export Results option in Search Results module).
Does it help? If not, or if you have any additional questions then let me know.