bootstrap popover-example

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<button 
    id="example"
    class="btn btn-lg btn-default"
    type="button"
    data-toggle="popover"
    data-placement="bottom"
>
Show Popover
</button>

CSS

button {
  margin: 2em;
}

li {
  white-space: nowrap;
}

.popover-content {
  overflow-x: scroll;
}

JavaScript

// enable popovers
$('#example').popover({

  html: true,
  content: `<ul>
     <li>Entry 1 ....................................................................</li>
     <li>Entry 2 ....................................................................</li>
     <li>Entry 3 .....................................................................</li>
</ul>`
});