String Input (Legacy), but there you will have to type the path or copy/paste it there.
Then pass this as variable to the List Files nodes.
Alternatively, if you still want to use a browse function, you could use
File Upload (legacy) where you select any file within your directory. From there you can either use Java Edit Variable to remove the ending and then pass the outcome to list-file, or if you don't like that you can use string to url where you receive the path in a column which in turn can be used with the file list node.