Glue screens and entities support folders inside of their Files object. Folders can be used to organize files and to support multiple files with the same name in a single screen or entity.
To add a folder to an existing screen or entity:
Right-click on the "Files" node under the screen or entity
Select "Add Folder"
Enter the new folder name and click "OK"
The newly-created folder will appear under the Files node. New files can be added to this folder.