Updated answer:
UI Router (which now sits here: https://angular-ui.github.io/ui-router/site/#/api/ui.router) is generally regarded as the best solution for complex routing in AngularJS.
Original answer:
Nesting views isn’t natively possible, as of now, in AngularJS. In my last app, I used a solution derived from here: http://www.bennadel.com/blog/2420-Mapping-AngularJS-Routes-Onto-URL-Parameters-And-Client-Side-Events.htm
Allowing me to effectively nest views (and skipping the limited ng-view altogether)
After doing so, this other (simpler, better, I believe) solution appeared:
http://angular-ui.github.com/ (scroll down to “Route Checking”)
Check it out!