Role based routing

I have this project where I have 4 roles and I don't know how to do a role based routing, most documentation I saw are just about returning one page for admin and other for the user, but my project is kinda bigger than that where the admin have a full dashboard also the user and guest have big nice interface, any idea how to do that Btw it's not a professional project, so I just wanna keep it clean and simple as possible