Range Product Formula

[m_perreault]

Hi All,

I have the below data

Period	Value
Dec-2018	-0.74%
Nov-2018	-0.33%
Oct-2018	0.22%
Sep-2018	0.65%
Aug-2018	0.79%
Jul-2018	0.75%
Jun-2018	0.59%

The for set time frames (such as QTD,YTD,etc.) I need to create a formula such as the one below.  This would be for QTD

(Aggr(Sum({<[Period] = {'Dec - 2018'}>}Value)+1,Period) * 

Aggr(Sum({<[Period] = {'Nov - 2018'}>}Value)+1,Period) *

Aggr(Sum({<[Period] = {'Oct - 2018'}>}Value+1,Period))-1

so my formula would = ((-.74+1)+(-.33+1)+(.22+1))-1 = -.0845

Does anyone have an idea of how to make this formula dynamic for a set period ?