There seem to be several common search scenarios that lead to dead-ends in older versions of AUI documentation.
First, many search items (e.g. “Atlassian AUI Button”) result in top results that lead to v7.7.9 documentation (https://aui.atlassian.com/aui/7.9/docs/buttons.html). In this version of the documentation, all menus in the navigation bar seem to be broken, including the version selector.
Other searches (e.g. “Atlassian AUI Tooltips”) seem to produce top results that lead to other older versions of the documentation (https://aui.atlassian.com/aui/7.8/docs/tooltips.html), and in some of these versions the version selector works, but leads to pages that produce 404/Page Not Found errors.
It would be pretty helpful if these broken navigation mechanisms could be fixed so that people coming to the documentation from these kinds of searches could more easily find their way to what they are looking for.