Hello @bkhl ,
It is possible using ostree. I have done this in trying to troubleshoot some issues early in SB use for me. Please refer to this discussion here https://discussion.fedoraproject.org/t/how-to-find-previous-images-earlier-than-rpm-ostree-rollback-or-the-boot-screen-allow-you-to-access/1019/4. Good luck.