Explanation:
Box 1: C:\Windows\policyDefinitions
The fslogix.admx file, which contains language-neutral Group Policy settings, should be copied to the %systemroot%\\policyDefinitions folder.
Box 2: C:\Windows\policyDefinitions\en-US
The corresponding fslogix.adml file, which contains the language-specific settings, should be copied to the %systemroot%\\policyDefinitions[MUIculture] folder. For example, the English language-specific file should be copied to %systemroot%\\policyDefinitions\\en-US.
These locations allow the Group Policy Management tool to correctly load and use the FSLogix settings when configuring user profiles in Azure Virtual Desktop.
Reference:
https://learn.microsoft.com/en-us/fslogix/how-to-use-group-policy-templates