Trying to read a file in a subdirectory through a module I imported from that subdirectory

So I have a program with one main module that is in a folder with two other folders. Each of those two folders has a module in it that I've imported successfully, but each of those modules is supposed to be able to open and read a file from their respective folders, but it is unable to find the file it is supposed to import. I think it is looking in the main directory for the file to open, how would I make each module look in its own folder for the files to open?