If you need to add a button over your slide, you can use either text or button layer. To specify the layer, you need to use ms-layer class name and set the type by data-type="button" or data-type="text"same as other layer types. The example below shows how to add a button over a slide.
<div id="masterslider" class="master-slider">
<div class="ms-slide">
<!-- .... -->
<a href="#" data-type="button" class="ms-layer">
Button label
</a>
<!-- or -->
<div class="ms-layer" data-type="text">
<a href="#">
Button label
</a>
</div>
<!-- .... -->
</div>
<!-- .... -->
</div>
This article only describes how to create a button layer. If you need more information about layers, check out the following articles: