Yes... you can dual boot Linux Lite and Linux "X".. Mint, Manjaro, Ubuntu or whatever...
Are you not seeing the other Linux distro in Grub? Linux Lite likes to be the primary Grub.. There are a few thing that need to be done..
But the folks will need to know what distros (order of install - assuming LL was installed prior).. Preferably how installed, side by side, custom = how the partitions configured and if you know, where the distro's grub was installed???
- i.e., you installed Mint and installed Mints grub to the root of the Mints partition...
If this sounds like where you're having issues - give this thread a look over:
https://www.linuxliteos.com/forums/installing-linux-lite/need-help-with-linux-lite-boot-issue-please/ Specifically gold_finger's response...