title: how to display content based on selected value react
body: <p>I have a array of objects</p>
  <pre><code>const people = [
      {
          group: 'senior'
          name: 'Yoda'
      },
      {
          group: 'youth'
          name: 'Kitty'
      },
      {
          group: 'adult'
          name: 'Lisa'
      },
  ]
  </code></pre>
  <p>I stored the group in the dropdown list. If selecting all from the dropdown, all objects will display, if selecting senior from the dropdown, only the object has the senior value will display.</p>
  <p>What's a good approach to do this in react?</p>