Nested display implementation of vue router-view

const routes = [
  {
    path: '/',
    name: 'Navigation 1',
    component: Home,
    children:[
      {
        path: '/customer',
        name: 'Customer',
        // route level code-splitting
        // this generates a separate chunk (about.[hash].js) for this route
        // which is lazy-loaded when the route is visited.
        component: () => import(/* webpackChunkName: "about" */ '../views/Customer.vue')
      },
      {
        path: '/pageOne',
        name: 'Page 1',
        component: PageOne,

      },
      {
        path: '/pageTwo',
        name: 'Page 2',
        component: PageTwo,
    },
    ]
  },
  {
    path: '/navigation',
    name: 'Navigation 2',
    component: Home,
    children:[
      {
        path: '/pageThree',
        name: 'Page 3',
        component: PageThree,

      },
      {
        path: '/pageFour',
        name: 'Page 4',
        component: PageFour
      },
    ]
  },

// An highlighted block
 <router-view></router-view>

// An highlighted block
<template>
  <div>
  <el-container style="height: 500px; border: 1px solid #eee">
    <el-aside width="200px" style="background-color: rgb(238, 241, 246)">

      <el-menu>
        <el-submenu v-for="(item,index) in $router.options.routes" :index="index+''">
        <template slot="title"><i class="el-icon-sell"></i>{{item.name}}</template>
          <el-menu-item v-for="(item2,index2) in item.children" :index="index+'-'+index2">{{item2.name}}</el-menu-item>
        </el-submenu>
      </el-menu>
    </el-aside>

    <el-container>
      <el-header style="text-align: right; font-size: 12px">
        <el-dropdown>
          <i class="el-icon-setting" style="margin-right: 15px"></i>
          <el-dropdown-menu slot="dropdown">
            <el-dropdown-item>View</el-dropdown-item>
            <el-dropdown-item>New</el-dropdown-item>
            <el-dropdown-item>Delete</el-dropdown-item>
          </el-dropdown-menu>
        </el-dropdown>
        <span>Wang Xiaohu</span>
      </el-header>

      <el-main>
        <router-view></router-view>

      </el-main>
    </el-container>

  </el-container>

</div>
</template>

<style>
.el-header {
  background-color: #B3C0D1;
  color: #333;
  line-height: 60px;
}

.el-aside {
  color: #333;
}
</style>

<script>
export default {

};
</script>