SOURCE

new Vue({
  el:"#app",
  data(){
    return{
      open:0
    }
  },
  methods:{
    openMore(open){
      this.open=open
    }
  }
})

<div id="app">
  <ul>
    <li>
      <button @click="openMore(1)">更多</button>
      <div class="more" v-show="open==1">更多</div>
    </li>
    <hr />
     <li>
      <button @click="openMore(2)">更多</button>
      <div class="more" v-show="open==2">更多</div>
    </li>
    <hr />
     <li>
      <button @click="openMore(3)">更多</button>
      <div class="more" v-show="open==3">更多</div>
    </li>
  </ul>
</div>

ul,li{
  list-style:none;
}