sudo can't be used for filesystem access directly: it only tells you which commands a user is allowed to run.
What you could do is to write a set of scripts that will let your developers read your system files, and configure sudo to only run those scripts. They could even be fairly simple scripts, i.e
Another option would be to set up a read-only samba share containing the files, and give the developers password-protected access to that. That way, they don't even need shell access to the machine.