<div class="btn-toolbar">
  <div class="btn-group me-2">
    <button type="button" class="btn btn-default">1</button>
    <button type="button" class="btn btn-default">2</button>
    <button type="button" class="btn btn-default">3</button>
    <button type="button" class="btn btn-default">4</button>
  </div>
  <div class="btn-group me-2">
    <button type="button" class="btn btn-default">5</button>
    <button type="button" class="btn btn-default">6</button>
    <button type="button" class="btn btn-default">7</button>
  </div>
  <div class="btn-group">
    <button type="button" class="btn btn-default">8</button>
  </div>
</div>