Let's say that you have a Section 1256 losse on 2022 return, and you want to carryback. So you can carryback to 2019, 2020 and 2021. You will need to file 1040X in the order of 2019, 2020, and 2021. However, you can also carryback all the losses to 2021, and only file 1040X for 2021.
