Thank you for using Bitnami. Checking this Discourse support ticket, they mention that you will need to use symlinks and rsync to use a different path.
#Copy the current backups to the new folder
cp -r /path/to/default/backups/backup-file /new/path/backups
#Remove the backups folder if that's empty and create a new symlink
rm -rf /path/to/default/backups/
ln -sf /new/path/backups /path/to/default/backups
Let us know if you have any questions. I also suggest you ask in the Discourse forum to know if there is any other way to solve this, the post I shared is quite old.