router => index.js

import Vue from 'vue'
import Router from 'vue-router'
import TOP from '@/components/top.vue'

Vue.use(Router)

export default new Router({
  routes: [
    {
      path:'/',
      components:{
        top:TOP,
        bottom:()=> import ('../components/bottom.vue')
      }
    },
    {
      path:'/b2',
      components:{
        top:TOP,
        bottom:()=> import('../components/bottom2.vue')
      }
    }
  ]
})

　架構：

<template>
    <div>
      <h1>我是上邊的元件</h1>
      <a @click="goB2">b2</a>
      <a @click="goB1">b1</a>
    </div>

</template>
<script>
export default {
    methods:{
        goB1(){
            this.$router.push('/');
        },
        goB2(){
            this.$router.push('b2');
        }
    }
}
</script>

　　bottom2 && bottom

<template>
    <h1>我是下邊的第二個元件</h1>
</template>

<template>
    <h1>我是下邊的元件</h1>
</template>

　　效果圖：