Ranking and Sum of Other Results / Keeping ranking in Charts

Hello to the community,

I'm a beginner on SAP BO and trying to get around a problem.

I've a table of data, and inserted a Top 15 ranking (over hundreds of results).

I would like to :

- Insert an "Others" lane below the Top 15, to display the totals of all other results. I tried to use the following instructions, but did not get any results.

http://scn.sap.com/community/businessobjects-web-intelligence/blog/2014/01/07/pie-chart-with-ranking-and-others-in-web-intelligence

I am ranking values, not percentage, with a very simple formula:

=Rank([SingleMonth].[Market Chargeable Weight])

Then I create the detail as follows:

=If([Agent Ranking (Chargeable Weight)]<15;[SingleMonth].[Market Chargeable Weight])In([SingleMonth].[Market Chargeable Weight])

If I drag and drop this detail where I would need to see the results, then I am just getting  no value (attached image NoValue)

- Keep the Top 15 in the Pie Chart, currently it's picking up the complete set of data from the results, not only the Top15. I guess this is related to the above.

Thanks in advance for your support and feedback !