we can achieve it by using Ranks.
And we have to be so cautious while defining Addressing & Partitions with respect to Business Requirement.
Top 5 by what measure? Top 5 under what ranking function?
Check out this regarding pie chart that keeps top % slices and group low %
Top 5 may mean different things:
I want % spending on product categories .maximum
5top categories of customer.
I.e it must show of each customer .pie chart preferred
First do the analysis i.e. create the piecharts and complete the required calculation then create a parameter for the calculation such that it will show the top 5 or according to the condition given.
Go through this link http://kb.tableau.com/articles/knowledgebase/Changing-Views-Using-Parameters