how to change data on a master list and have the change reflected on the proper worksheet?

Hi EBexcel and welcome to the forum

It sounds like you need to use vlookup or index/match, but without seeing what you are working with, where you want the answers etc, its hard to say.

i would suggest you upload a sample work book, (all sensitive data removed), showing what data you are working with, a few examples of what your expected outcome is, and how you arrived at that
To attach a file to your post,
click advanced (next to quick post),
scroll down until you see "manage file",
click that and select "add files" (top right corner).
click "select files" find your file, click "open" click "upload" click 'done" bottom right. click "submit reply"

Once the upload is completed the file name will appear below the input boxes in this window.
You can then close the window to return to the new post screen.

I am posting a sample of the problem I am working on.Attachment 211371

Hi, Thank for the file, but I removed it because it looked like it contained sensitive (salary and names?) info

If this is not the case, then please upload again, if I was correct, then please replace names etc with dummy data, and upload again.

Either way, when you upload again, pleas, as requested, include a few examples of what your expected outcome is, and how you arrived at that, so that I can see what you are trying to achieve