Dropdown Within a Dropdown
<p>I am just wondering how to make a dropdown menu with another dropdown inside of it, so for instance:</p>

<pre><code>Dropdown Title
    Title 1
    Title 2
       Item 1
       Item 2
       Item 3
    Title 3
</code></pre>

<p>I have made a single dropdown menu so far:</p>

<pre><code>&lt;li class="dropdown"&gt;
    &lt;a class="dropbtn"&gt;Novel&lt;/a&gt;
    &lt;div class="dropdown-content"&gt;
        &lt;a class="dropbtn"&gt;&lt;h3&gt;Volume 1&lt;/h3&gt;&lt;/a&gt;
        &lt;a href="index1.html"&gt;Chapter 1&lt;/a&gt;
        &lt;a href="index2.html"&gt;Chapter 2&lt;/a&gt;
        &lt;a href="index3.html"&gt;Chapter 3&lt;/a&gt;
        &lt;a href="index4.html"&gt;Chapter 4&lt;/a&gt;
        &lt;a href="index5.html"&gt;Chapter 5&lt;/a&gt;
        &lt;a href="index6.html"&gt;Chapter 6&lt;/a&gt;
    &lt;/div&gt;
&lt;/li&gt;
</code></pre>

<p>I have literally no idea how to make the second dropdown menu - which will come from the "Volume 1" h3. I also think it will be best to keep it in the vertical orientation. Thanks in advance.</p>