Salesforce Flow - Roll-Up Summary Nested Loop Automation?

Question

I am trying to roll-up different fiscal year's projection sums to three different fields in Opportunities. Is there a way to do it within the same flow automation?

There is a master-detailed relationship between Opportunities(Parent) to Projections(Child). One opportunity may have one or more projection records in different fiscal years.

Fields involved:

• Opportunities.[This FY Projected Amount]
• Opportunities.[Last FY Projected Amount]
• Opportunities.[Next FY Projected Amount]
• Projections.[Fiscal Year Calendar] --> This is a formula field (thus, I can't just set up a roll-up summary field) that evaluates which fiscal year the projection record is in. It is used as a criteria to filter out the projection records.

I want to loop through a collection of projections record and update the specific FY projected amount field. However, it looks like there is no easy way to break out of the flow within one flow.

Is there a way to do that? I don't want three seperate flows. Preferably, this will have to be a scheduled flow to run every night to keep the fields updated.

Rol-Up Summary Fields from Projections to Opportunity