It requires going up in to a parent directory then another parent, then going in a different child > child > thefile.rb.
I've looked through a few posts and all of them seem to be if the files are in pretty much the same directory.
At the moment I have
load '../../lib/classes/X.rb'
load '../../lib/classes/Y.rb'
load '../../lib/modules/Z.rb'
Everytime I get the error "cannot load such file"
Is there anything I'm missing here?
It's worth trying to load the files in irb first to see if you've got syntax or anything incorrect. I just tried writing nearly exactly the same as you (directory names are different) but it all worked fine.
irb(main):002:0> load '../../Work/Z.rb'
=> true