On one hard drive, I have a library of movie files in a single folder, and on another "backup" hard drive, I have the same files only sorted into different folders and subfolders (e.g. by country, director, etc.). The purpose of this setup is not important, but I'll add that the single-folder drive is used for torrenting.
If my backup drive with multiple folders and subfolders fails, I want to be able to automatically restore the files from the single-folder drive into their multi-folder structures.
Note that this isn't a job for backup/recovery software, as I'm not interested in saving a backup of all the files. Nor is it a job that would involve simply copying the file directories to text/CSV file, or copying them as empty folders.
Basically, the thing being saved would act like a configuration file telling the OS into which folders/subfolders to place a list of files.
UPDATE: The original question is obsolete (for me) because the practice of maintaining one messy, single-folder drive and another organized, multi-folder drive (with the same files) as back-up is impractical and can be accomplished differently using symbolic links or hard links. Basically, these links allow us to have the same files located in different folders of a hard drive without taking up double the space, as would happen if we made copies of them. So, for example, we can have the files in a single folder (for seeding purposes) as well as organized in multiple folders on the same HDD. Thus, in contrast to the situation of having files organized differently across two hard drives, we can maintain a real backup of the hard drive without having to recreate the folder structures if one drive fails. Google these terms (symbolic and hard links) for more info.