I want to do the exact same thing and haven’t figured out if the following is the right way:
Modify the current btrfs volume to use only the SSD disk (in your screenshot both disks are selected). Use that volume for / .
Then create a new btrfs volume (click the volume name, a dropdown menu appears with the option, I believe) and make it use only the hdd disk. Use that volume for /home.
In theory this should work, but I did not go through with the installation, because I dualboot and was afraid of messing something something up. If you do try this, let me know if it worked.
Ah yes, that’s what I saw as well, misreporting the size of the different volumes.
Could either be just a visual bug, or a proper bug with the volume creation. Or maybe even it just doesn’t work like that.
Sorry can’t help you discern which it is, as I never did go through with installing it with btrfs. I see you have an unknown installation listed, probably means you are dualbooting with another Operating System as well? My initial suggestion was going to be “try and see if it works as you intendo to”, but it’s probably unsafe since you are running other OSes.
You could use the ext4 file system instead which is what I’m currently doing. Or file a bug report at https://bugzilla.redhat.com/ so fedora developers fix in for future releases (choosing Product Fedora and Component Anaconda). If you don’t want to, tell me, and I can do it.
The problem for me was that I couldn’t change the size of the Btrfs volume on my HDD. I got around this by deleting the /home mountpoint listed on the left-hand side of the screen and replacing it manually using the button with the addition sign on it. To fill the whole of my /dev/sdb HDD I just entered a size for the new volume in GB that was larger than the drive.
I’m not sure this qualifies as a bug but it’s certainly inconvenient that a new Btrfs volume can’t be easily resized to fill the whole drive using the Anaconda interface.