dva多层路由设置问题

Question

两层路由：const routes = [{  path: '/dashboard',//第一层路由  component: App,  getIndexRoute(nextState, cb) {},  childRoutes: [{//子路由    path: 'product',    getComponent(nextState, cb) {},  }],}]如果子路由里面再设置子路由该怎么设置呢？