Ruby on Rails further development

I've been developing a web app for my organisation to make managing the Human Resources a lot easier than a lot of spreadsheets. I have been developing it in Ruby on Rails and have used a variety of gems to get it working as I desire. I am currently stuck getting Ancestry to work how I want, where each employee has one or more roles and the roles are in a hierarchy. I want certain attributes of the employee to be editable by the employee themselves and some only by their line-manager. Certain roles/levels of hierarchy should be able to see certain bits of information about other people, which I would like to select. That's a basic outline of where I'm stuck. The repository is at [login to view URL] I don't think it would take someone who knows what they're doing very long to do, but would appreciate if you have any advice for me. I don't want to spend too much on this as it's a personal project really, but if you think you could also do more for cheap then I could get a quick specification drafted.