I already have a partition layout in btrfs where I have a /home and a /root partition, since when I installed I didn’t know about btrfs subvolumes. I use Void Linux and I think it’s after installation, since I don’t remeber having a subvolumes step during the installation.
I’ll make sure to remind about btrfs subvolumes in case I reinstall. There’s a btrfs program that has a subvolume argument, so I’m guessing that’s what I could use.