Managed Bookmarks subfolder

Hello, I would like to create Managed Bookmarks for our company and distribute them via Group Policy. However, I am unable to create subfolders for these Managed Bookmarks, so they would all be in one folder and quite disorganized, which is why I need subfolders. Can I map this using a JSON file, and if so, could someone assist me with the structure of the JSON file? Thank you in advance! Kind regards