Jim thanks for the suggestion, but it doesn't seem to be getting me where I need to be.  I am trying to visualize the Top N only for each year and be able to adjust for N as well as year. Unless I'm missing something, your suggestion seems to aggregate all of the causes that occurred in the  X-Year period and display them all for each year but shows a rank value.  SO for the example data given: Doing a Top 2 by year (2016 and 2017)   -  2016 would show (in descending order) Act of Nature  45, Inattention 37 and Positioning Body for task  30, then 2017 would show Inattention 45, None Applicable 30, and Act of nature 28. I am striving for a visualization similar to what is seen on my example worksheet "Using Rank on LOD expression".  I would eventually not display those items in the OUT set, but as you can see the set is triggering wrong on looking at the 2018 charting.

Maybe I'm missing a step?  Do I need to create a set using your LOD filter or Rank of LOD ?

Thanks Jim, I guess I had been looking t and thinking about this for too long and my thought process bogged down.  Your suggestion is just what I am looking for and it seems to be working perfectly.