Well, I am feeling a little dense this morning, so maybe somebody else will read this post and understand more clearly what you're trying to do! Crop I understand, but I don't understand "on the other side." But, I'm going to assume that you have one image and you want to crop two separate areas of it and make it into two images.
Personally, I don't use the crop tool. Try this and see if you get the results you're after.
Open your original image on the desktop and immediately go to Image>Duplicate Image - twice - and make two copies. Close the original. (I'm a fanatic about never working on the original!)
Select the Rectagular Marquee tool, draw an outline around the portion of the first duplicate image that you want to keep. Then Image>Crop. There's your first cropped picture. Now do the same thing on the second copy. There's your second cropped picture. Is that what you needed?
I don't like using the Crop tool, because it requires verifying each time that you've got any settings turned off that would give you a resampling. That's why I prefer cropping with the Rectangular Marquee. (I know you didn't ask, but I decided to volunteer!)
If you haven't gotten the instructions you need to complete your project, please repost, either with a little more detail or - with luck - somebody whose brain is firing on all cyclinders will see your message next time! :)