I wasn't aware that there was a difference between searching for google synced calendars and iCloud ones. I don't have any problems seeing older iCloud events. The list tends to show the next one, but scrolling up will show previous ones; if they exist.
Go to Settings > Calendars > Sync and make sure it's set to sync back as far as you want. It varies from 2 weeks to forever. Give it some time to catch up (or back). There isn't any setting that I know of on the iPad that would affect just Google calendars, so if this doesn't make any difference I can't think of anything that will.
In that case, you might end up having to visiting Google Calendars in Safari for this kind of thing. Hopefully you don't need to do it often.