How do I repair a corrupt Time Machine sparsebundle that is only showing the most recent backup?
Not completely sure if it will works since I don't know when the snapshot was taken (before or after an update).  You can go into your system preferences, spotlight, privacy tab, add your hard drive, reboot, remove the hard drive from spotlight and let the spotlight re-index (this can take a while).  Try going into time machine again.  

Updates have messed up Time Machine when doing a clean install and upgrade for quite a few people and this was the fix.