Getting the files your app stores on the device back out so you can look at them for debugging or similar is not as easy as it could be. There’s a number of filebrowser libraries out there, but it’s a bit overkill or occasional use and probrably not something you want to ship with your app either. Here’s how to create a zip file from any directory and move it off the device using the share sheet (UIActivityViewController).
Setting these UserDefaults in your app’s domain will change AppKit behavior at runtime.
Starting with Xcode 9 or so, Xcode by default keeps the on-disk layout of a project in sync with what you see in the Project Navigator. So when you move a file from one group to another, it will be moved between the respective folders on disk as well.