Automate splitting a large image into small screenshots with Photoshop

Automate splitting a large image into small screenshots with Photoshop

I have a big image and I need to make tens of small screenshots out of it with different sizes and aspect ratios (screenshots are only a small part of the big image that I need to select, all sizes are known and won't change). I figured out how to automate 1 screenshot but don't know how to make them all in one batch.