Sorry to resurrect this thread, on a fresh cachyos installation and with snapper and btrfs assistant seemingly setup and snapshots created after a few pacman commands, I am not seeing any bootable snapshots in the grub menu.
Following @vawaver instructions has now added the snapshots on boot grub menu.
@antonispgs just for info - here is my step-by-step video tutorial.
@vawaver I must just be lucky then.
sudo awk -F\' '$1=="menuentry " || $1=="submenu " {print i++ " : " $2}; /\smenuentry / {print "\t" i-1">"j++ " : " $2};' /boot/grub/grub.cfg
0 : CachyOS Linux
1 : Advanced options for CachyOS Linux
1>0 : CachyOS Linux, with Linux linux-cachyos-lto
1>1 : CachyOS Linux, with Linux linux-cachyos-lto (fallback initramfs)
1>2 : CachyOS Linux, with Linux linux-cachyos
1>3 : CachyOS Linux, with Linux linux-cachyos (fallback initramfs)
1>4 : UEFI Firmware Settings
2 : **CachyOS Linux snapshots**
But your tutorial is very nice for newer users and very kind of you share. 
paru snapper
1 cachyos-extra-v3/snapper 0.11.2-1.1 [0 B 2.91 MiB] [Installed]
A tool for managing BTRFS and LVM snapshots. It can create, diff and restore snapshots and
provides timelined auto-snapping.
2 extra/snapper 0.11.2-1 [788.34 KiB 2.72 MiB] [Installed: 0.11.2-1.1]
A tool for managing BTRFS and LVM snapshots. It can create, diff and restore snapshots and
provides timelined auto-snapping.
paru grub-btrfs
1 extra/grub-btrfs 4.13-2 [0 B 103.66 KiB] [Installed]
Include btrfs snapshots in GRUB boot options
Your Good People 
