The activity asks as input for the Folder in-argument a value that doesn’t include hosts or clusters and looks like a folders full-path, starting from the Datacenter - example: “Datacenter1/Folder1/Subfolder”
This full-path is what you see when you expand nodes in the VMware vSphere - VMs & Folders view (the one from your latest screenshot).
As a helper, you can take a look at:
- VMware sample video that includes GetVMsList Automate VMWare Activities with UiPath - YouTube
- VWware sample workflow guide (skip to How to use, step 5.) IT Automation Activities for VMWare