It's beyond support, but ...

Here's a complete example of a dropdown list using HTML and CSS. Hovering over the button displays a list of options.

Custom CSS (must be used in Page Settings > Custom CSS) :

    .dropdown {
      position: relative;
      display: inline-block;
    }

    .dropdown-button {
      padding: 10px 20px;
      font-size: 16px;
      background-color: #3498db;
      color: white;
      border: none;
      cursor: pointer;
      border-radius: 4px;
    }

    .dropdown-content {
      display: none;
      position: absolute;
      background-color: #f9f9f9;
      min-width: 160px;
      box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
      z-index: 1;
    }

    .dropdown-content a {
      color: black;
      padding: 12px 16px;
      text-decoration: none;
      display: block;
    }

    .dropdown-content a:hover {
      background-color: #f1f1f1;
    }

    .dropdown:hover .dropdown-content {
      display: block;
    }

    .dropdown:hover .dropdown-button {
      background-color: #2980b9;
    }

HTML Part - use it inside Raw HTML addon

<h3>Dropdown Menu Example</h3>
<div class="dropdown">
  <button class="dropdown-button">Select Option</button>
  <div class="dropdown-content">
    <a href="/link1">Option 1</a>
    <a href="/link2">Option 2</a>
    <a href="/link3">Option 3</a>
  </div>
</div>