CAGR(Compound Annual Growth Rate) Calculation in OTBI

Summary:

Creating an OTBI analysis to calculate CAGR of the joiners in my org in last 3 years.

Content (required):

I am trying to calculate CAGR of the joiners in my org in last 3 years from the current date in OTBI using the below CAGR formula -

CAGR = ((Headcount on the end date of the period/Headcount on the start date of the period) ^ 1/no. of years) - 1

I am getting the correct headcount on the current date but I am facing problems getting the correct headcount on current date minus 3 years (i.e. 16-02-2020 if we are calculating today).

Can anyone suggest a way to do that?