title: Adding a multiselect to a dropdown menu
body: <p>I'm trying to get a multiselect selector from bootstrap-select in my dropdown from bootstrap 4.
  But every time I try to open the multiselect my dropdown menu closes and I can't figure out why this happens or how to prevent it.
  In the same dropdown menu I have a normal selector and that does the exact same thing.</p>
  <pre><code>&lt;a data-toggle=&quot;dropdown&quot; aria-haspopup=&quot;true&quot; aria-expanded=&quot;false&quot; href=&quot;#&quot;&gt;
      &lt;button style=&quot;margin-top: 10px; margin-left: 10px;&quot; class='btn btn-success'&gt;Nieuwe module&lt;/button&gt;
  &lt;/a&gt;
  &lt;div class=&quot;dropdown-menu&quot; style=&quot;margin-top: 25px !important;&quot;&gt;
      &lt;div style=&quot;margin-left: 10px; margin-right: 10px;&quot;&gt;
          &lt;h5 class=&quot;card-title&quot;&gt;Nieuwe module toevoegen&lt;/h5&gt;
          &lt;form action=&quot;modulemanager.php&quot; method=&quot;post&quot;&gt;
              &lt;div class=&quot;form-group&quot;&gt;
                  &lt;label&gt;Termijn&lt;/label&gt;
                  &lt;select name=&quot;newtermijn&quot; class=&quot;form-control&quot;&gt;
                      &lt;option value=&quot;0&quot; selected&gt;Eenmalig&lt;/option&gt;
                      &lt;option value=&quot;1&quot;&gt;Per maand&lt;/option&gt;
                      &lt;option value=&quot;2&quot;&gt;Per jaar&lt;/option&gt;
                  &lt;/select&gt;
              &lt;/div&gt;
              &lt;div class=&quot;form-group&quot;&gt;
                  &lt;label&gt;Categorie&lt;/label&gt;
                  &lt;select name=&quot;newcat[]&quot; class=&quot;selectpicker&quot; multiple title=&quot;Kies categorieën&quot;&gt;
                      &lt;option value=&quot;0&quot; selected&gt;Eenmalig&lt;/option&gt;
                      &lt;option value=&quot;1&quot;&gt;Per maand&lt;/option&gt;
                      &lt;option value=&quot;2&quot;&gt;Per jaar&lt;/option&gt;&gt;
                  &lt;/select&gt;
              &lt;/div&gt;
              &lt;button type=&quot;submit&quot; name=&quot;add&quot; class=&quot;btn btn-primary&quot;&gt;Toevoegen&lt;/button&gt;
          &lt;/form&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  <p>I found <a href="https://stackoverflow.com/questions/25443347/show-bootstrap-select-inside-bootstrap-button-dropdown">this</a> solution that made the normal select work but not the bootstrap-select dropdown</p>