如何在选项卡中显示分层术语列表

<div class="tabs">
  <ul class="tab-nav">
    <li class="active">选项卡1</li>
    <li>选项卡2</li>
    <li>选项卡3</li>
  </ul>
  <div class="tab-content">
    <ul class="term-list">
      <li>术语1</li>
      <li>术语2</li>
      <li>术语3</li>
    </ul>
    <ul class="term-list">
      <li>术语4</li>
      <li>术语5</li>
      <li>术语6</li>
    </ul>
    <ul class="term-list">
      <li>术语7</li>
      <li>术语8</li>
      <li>术语9</li>
    </ul>
  </div>
</div>

.tabs {
  width: 100%;
}

.tab-nav {
  list-style: none;
  padding: 0;
  margin: 0;
}

.tab-nav li {
  display: inline-block;
  padding: 10px 20px;
  background-color: #ccc;
  cursor: pointer;
}

.tab-nav li.active {
  background-color: #f00;
  color: #fff;
}

.tab-content {
  display: none;
}

.term-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.term-list li {
  margin-left: 20px;
}

var tabNav = document.querySelectorAll('.tab-nav li');
var tabContent = document.querySelectorAll('.tab-content');

for (var i = 0; i < tabNav.length; i++) {
  tabNav[i].addEventListener('click', function() {
    var tabId = this.getAttribute('data-tab');

    for (var j = 0; j < tabContent.length; j++) {
      tabContent[j].style.display = 'none';
    }

    document.getElementById(tabId).style.display = 'block';
  });
}