Explorer Window
The Explorer window displays all search paths defined for the selected SchemaAgent Server as well as the relevant files contained herein. Depending on your installation, these search paths can be configured directly in the Configure Paths tab (if you are connected to a LocalServer) or in SchemaAgent Server (if you are connected to a network-based server). Consequently, the Configure Paths tab is visible only if you are connected to a LocalServer.
Hierarchical Tab
The Hierarchical tab shows all the defined search paths and their contents. Folders that contain supported file types have the standard Windows appearance. Folders that contain no such files are slightly opaque, like the Import folder in the image below.
To hide folders that contain no supported files, right-click inside the window and select Show Empty Folders from the context menu.
Flat Tab
The Flat tab displays a flat list of all monitored files in all search paths, as well as all schemas from the External files folder (that is, schemas referenced by schemas in the search paths, but which are not themselves in any search path), if such schemas exist. Each file entry is displayed with its location and its status.
In the screenshot above, note the different icons used to indicate ghost files 
and files with unresolved relations 
.