Here is an example of how it works:
Pretty neat, right? This should allow you to capture key moments in the heat of battle without having to tab so much between chat windows. There may be additional changes so that you can also filter out chat messages on the Main tab at all, but no promises.
Eventually we'll have more sorts of filters such as attacks, attacks on self, etc. It isn't fully possible just yet as it requires editing all the messages and that is a big thing to do right now.
Hope you guys will enjoy it!