<template>
  <div>
    <ul>
      <li v-for="item1 in items1" :key="item1.id">
        <span>{{ item1.name }}</span>
        <ul>
          <li v-for="item2 in item1.items2" :key="item2.id">
            <span>{{ item2.name }}</span>
          </li>
        </ul>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      items1: [
        { id: 1, name: 'Item 1', items2: [{ id: 1, name: 'Subitem 1' }, { id: 2, name: 'Subitem 2' }] },
        { id: 2, name: 'Item 2', items2: [{ id: 3, name: 'Subitem 3' }, { id: 4, name: 'Subitem 4' }] },
      ]
    };
  }
};
</script>