About Searching in forums

This is the point, in the old grasshopper forum there is a lot of info in some cases I be able to resolve some doubts just searching in the forum now you mixed the searching data with thisone and is difficult get some viable ways to resolve the doubts whitout ask, couse you have to search in a lot of topics I tried even adding tag grasshopper and many pages are from this forum in tags like Rhino, Developer or another tags.

What is the way to search just in the old topics?