User blog comment:Rupert Giles/Introducing Updated Global Navigation/@comment-5645428-20141023130257/@comment-24025240-20141028175301

While it's true that the text currently indicates where you are searching this is actually a half step. The plan is to have a single search bar that will return results from around Wikia. We haven't fully scoped out what the experience would be yet but it's likely that fitlering to the individual community will be handled via an account setting (always search locally), filters on the search results, or filters on search suggestions.

The intention with the global nav right now is to acclimate users to the design and placement of the search in global nav while we work on the richer search experience.