How can I retrieve the individual amounts of my different pensions for prior tax returns, since the returns only have the total of all pensions?

[pnberkowtaxes201]

I need this, going back to 2017, in order to prove something to the Social Security Administration.

[Opus 17]

You can try to get your tax account transcripts, particular your wage and income transcripts.  That should list each 1099-R individually.  Transcripts should go back 10 years. 

https://www.irs.gov/individuals/get-transcript

If your 1099-Rs are not in your transcripts, then there is no other way to get the information from the IRS or Turbotax.  You would have to contact the individual payers.