A joint tax return shows only the combined income for both spouses. There is no way to find your individual incomes in the actual tax return itself, because the information simply isn't there. To find your individual incomes, you have to look at your W-2s or your own records of your separate incomes. You might also have some joint income, such as investment income from a jointly owned account. You will have to decide how to handle that if you are trying to determine your individual incomes.
If you did not save your W-2s, you can download a PDF from TurboTax with all forms and worksheets, not just the forms for filing. It will include a W-2 worksheet for each W-2 that you entered, containing the income information from the W-2.
Another way to get the information is for each of you to get a Wage and Income Transcript from the IRS. This will list the information from your W-2s. A Wage and Income Transcript is for one person, so you each have to get one. You need a Wage and Income Transcript, not a Tax Return Transcript. You can get a Wage and Income Transcript at the following link on the IRS web site.
https://www.irs.gov/individuals/get-transcript
EDIT: Added link
