Creating a Trend

[JoannaManibo]

Hi - What would be the best approach or logic to use if I want to create a trend by adding dimensions to each group. 

For example:

Previous FY - Bar should only reflect "Previous FY" Data only

FY-2015 - Bar should reflect "Previous FY" + "FY-2015" data to create a trend

FY-2016 - Bar should reflect "Previous FY" + "FY-2015" + "FY-2016" data to create a trend