Steve Jones shows us how to restore a backup striped across multiple files:
Each of these is part of a striped backup, a piece of a backup file. To restore the backup, I need all the files to reassemble the backup. This is fairly simple, but you should be aware of how this works and how to perform a restore.
In my case, you can see I have 7 files for each database. They are the same name with an _0x at the end, with x being the number of the file.
Take Steve’s advice and script out the restore process. That way you know how to do it next time, can start building automation scripts, and can make your life easier.