Create FY22 revenue field - based on sum of different revenue components with date of expected revenue between 31st March'21 and 31st March'22

Create FY22 revenue field - based on sum of different revenue components with date of expected revenue between 31st March'21 and 31st March'22

Hi,
We have 2 revenue components, ARR - Annual recurring revenue, it is a monthly payment that our customer give us.
Second is COR - this is the cost of implementation

We have made projections on these revenues for deals in pipeline which extend to FY22, 23, 24

I need a field in deals which gives me sum of ARR and COR if their billing date is in FY22, so I can get revenue projections for FY22. 

How do I do this?
Please note that the ARR component is in a subform and the dates are in a subform field called 'billing date', while the COR dates have 3 fields in the deals module - COR 1 date, COR 2 date, and COR 3 date.