Showing last 12 months based on end date

Hello! I'm struggling to build the following logic for my report:

I need to show last 12 months data based on time frame selected. For example, if the user selects 04/2021 - 09/2022 time frame - the chart should only show 12 months before 09/2022.

Another example, if the time frame is shorter, lets say 06/2022 - 08/2022, show  12 months before 08/2022. 

Please help 😞