Mount only a part of a disk to a folder

Hi have the following problem.

I have a disk /dev/sda1 mounted on /. The same disk contains a /home directory and I want to mount only that directory on a /backup mount-point because I have a third party script that require to read data in /backup

In the /etc/fstab the string that mount the disk to the root / is the following:

UUID=a72d084b-4bd2-4f05-a223-4e94ca2349aa / ext4 errors=remount-ro 0  1

I think it does not make sense to mount a subfolder of a disk to another folder inside the same disk and that a symlink should do the work, but is there a way to do this with mount?