The attached example shows the content of your root folder as a tree.
It makes use of Miscellaneous/Get Folder Contents to retrieve the contents of a folder specified via the <Folder URL> trigger.
The <Folder URL> trigger expects a file: url which can be created by passing the folder path (specified in your server OS's regular format) via Miscellaneous/Create File URL.
I hope this helps youy get started.
For best results, use the Firefox browser..