How would I find the Top N of this view? I have found myself unable to do it through the conventional methods (index or ranking). It is important that one can still filter on a variety of different filters. Thanks!
Drag an instance of customer name onto the filters shelf. Go to the 'top tab' of the filter.
From here choose the calc field that you've created and select the top 10. The issue you will have here now is how to treat ties, wherein multiple people have 4 as the time, but only a few 4's are included.