There is a Total Subtraction of $31,979 to my RI taxes. I know this is from the NET Modifications to Federal AGI for SSA and Retirement, but how was this calculated?

The modifications decreasing the Federal AGI are all reported on RI Schedule M.  There are two separate lines on Schedule M for taxable Social Security and Retirement Income.  The explanation for determining the Retirement Income modification is in the 2022 1040R Instructions on page I-8.  

The Social Security modification is calculated on a separate form and is then transferred to Schedule M.  Here is a link to the form that is used for this calculation:  Taxable Social Security Income Worksheet

Also, for your reference, here is a link to the Schedule M:  RI Modifications to Federal AGI

Annette, thank you so much for your response.  I had such a hard time finding the information.