You cannot switch between tabs in this static demo because it does not contain the JavaScript to handle this behavior. The demo is here to show the look of tabs and the DOM structure.
<ul id="demoTabs" class="nav" role="tablist">
<li role="presentation" class="nav-item">
<button id="tab1" class="btn btn-link nav-link active" aria-controls="panel1"
aria-selected="true" type="button">Dashboard</button>
</li>
<li role="presentation" class="nav-item">
<button id="tab2" class="btn btn-link nav-link" aria-controls="panel2"
aria-selected="false" type="button">Management</button>
</li>
<li role="presentation" class="nav-item">
<button id="tab3" class="btn btn-link nav-link" aria-controls="panel3"
aria-selected="false" type="button">Cloud</button>
</li>
</ul>
<section id="panel1" role="tabpanel" aria-labelledby="tab1">
...
</section>
<section id="panel2" role="tabpanel" aria-labelledby="tab2" aria-hidden="true">
...
</section>
<section id="panel3" role="tabpanel" aria-labelledby="tab3" aria-hidden="true">
...
</section>