Restore from backup with files does not ask to use those files

Hi. I have restored a full backup with files in a new computer (Mac OS). I did the backup in the old computer including the music files. And I read this post before writing now where it says that when you restore from backup with files you are prompted to ask you where do you want to store those files.

But the thing is when I made the restoration process, everything went fine, but the database structure is same like the old computer, pointing all the files to its original location. Someone in external drives that work correcly connecting the external drives, and some of them in the local hard disk. Oviously as I don't have them, will have to reallocate. 

But my question is, for what are the music files included in the backup ?

When I tried to start restoration without connecting the external hard drives, it would ask me "where to store the music files that could not be put it is in original place". But when I canceled and restart the process connection those hard drives , I was not prompted for anything.

So, how can I use those files and for what are those files included in the backup? Because the structure of the files when copied in the backup drive are similar that the one is created when exporting music to USB devices.

Hope I have explained myself well because it's a very particular and concrete question, for which I have not found answer checking everywhere.

Thanks!