I've been referring to the bootstrap 4 documentation for my project.
After copying and pasting the code snippet for vertical pills, I noticed it wasn't functioning correctly.
Instead of displaying text next to the buttons, it was appearing below them, and the button pills were too wide.
<html>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
<div class="nav flex-column nav-pills" id="v-pills-tab" role="tablist" aria-orientation="vertical">
<a class="nav-link active" id="v-pills-home-tab" data-toggle="pill" href="#v-pills-home" role="tab" aria-controls="v-pills-home" aria-selected="true">Home</a>
<a class="nav-link" id="v-pills-profile-tab" data-toggle="pill" href="#v-pills-profile" role="tab" aria-controls="v-pills-profile" aria-selected="false">Profile</a>
<a class="nav-link" id="v-pills-messages-tab" data-toggle="pill" href="#v-pills-messages" role="tab" aria-controls="v-pills-messages" aria-selected="false">Messages</a>
<a class="nav-link" id="v-pills-settings-tab" data-toggle="pill" href="#v-pills-settings" role="tab" aria-controls="v-pills-settings" aria-selected="false">Settings</a>
</div>
<div class="tab-content" id="v-pills-tabContent">
<div class="tab-pane fade show active" id="v-pills-home" role="tabpanel" aria-labelledby="v-pills-home-tab">test1</div>
<div class="tab-pane fade" id="v-pills-profile" role="tabpanel" aria-labelledby="v-pills-profile-tab">test2</div>
<div class="tab-pane fade" id="v-pills-messages" role="tabpanel" aria-labelledby="v-pills-messages-tab">test3</div>
<div class="tab-pane fade" id="v-pills-settings" role="tabpanel" aria-labelledby="v-pills-settings-tab">test4</div>
</div>
</html>