Last month of Quarter - Date Lists & Formulates

I need to create a rollforward which is a Quarterly rollforward (see SNIP below of rough draft). This will past 5 quarters of data. I will be creating formulas for each of the listed items (Beginning Bal, additions etc). I would like some help in creating either lists or formulates so that way I can pick the last available month of the date from the model for each quarter.  In our model we have monthly load dates but we do not have Quarter dates. When I select 2025 I'd like to see 03/31/25 data for 2025-Q1 and 05/31/2025 for Q2 as we do not have 06/30/25 data loaded yet. What would be an ideal way to create a list so that only the last month of the Quarter is selected and also have 5 quarters data in the report.

 

 

 Thank you