install linux into directory?

install linux into directory?

I have linux (Debian Jessie) installed on hard drive. Drive - sda1,
ext4fs, and sda2 - swap
I have /chroot folder. There is installed another system, in /chroot folder.
Question:
How to tell bootmanager, to boot not _primary_ system (main, Debian
Jessie), but system in /chroot? Probably, change /menu.lst and
/chroot/etc/fstab? ("vmlinuz root=/dev/sda1/chroot"?)
Or another variant of question: is it possible, to have linux installed
not into root directory of partition, but in folder? (/another_linux/bin,
/another_linux/home, /another_linux/etc, ...)
Thank you for any hint!