If you use flurry analytics you can easily do this. If you are looking for an iTunes Connect or Apple way of doing this there is no feature.
Flurry is 100% free to use and extremely easy to install into your app. It's pretty much drag and drop a few imports and then you're just added one line of code to track specific things.
How I suggest you do this is insert the [FlurryAPI logEvent:@"EVENT_NAME"]
call in the same statement that you call an achievement in your iOS game.
Currently you can see in my game what the analytics look like: