I recently came across a carousel demo with thumbnails using bootstrap 3 which you can view here.
I attempted to replicate this using bootstrap v4, but encountered difficulties with the left/right shadows overlapping the thumbnails. You can see my attempt with v4 here.
Below is the HTML code:
<div id='carousel-custom' class='carousel slide' data-ride='carousel'>
<!-- Wrapper for slides -->
<div class='carousel-inner'>
<div class='carousel-item active'>
<img src='http://placehold.it/400x200&text=slide1' alt='' />
</div>
<div class='carousel-item'>
<img src='http://placehold.it/400x200&text=slide2' alt='' />
</div>
<div class='carousel-item'>
<img src='http://placehold.it/400x200&text=slide3' alt='' />
</div>
</div>
<!-- Controls -->
<a class='left carousel-control' href='#carousel-custom' data-slide='prev'>
<span class='glyphicon glyphicon-chevron-left'></span>
</a>
<a class='right carousel-control' href='#carousel-custom' data-slide='next'>
<span class='glyphicon glyphicon-chevron-right'></span>
</a>
<!-- Indicators -->
<ol class='carousel-indicators'>
<li data-target='#carousel-custom' data-slide-to='0' class='active'><img
src='http://placehold.it/100x50&text=slide1' alt='' /></li>
<li data-target='#carousel-custom' data-slide-to='1'><img src='http://placehold.it/100x50&text=slide2' alt='' />
</li>
<li data-target='#carousel-custom' data-slide-to='2'><img src='http://placehold.it/100x50&text=slide3' alt='' />
</li>
</ol>
</div>
For CSS Changes:
#carousel-example-generic {
margin: 20px auto;
width: 400px;
}
#carousel-custom {
margin: 20px auto;
width: 400px;
}
#carousel-custom .carousel-indicators {
margin: 10px 0 0;
overflow: auto;
position: static;
text-align: left;
white-space: nowrap;
width: 100%;
}
#carousel-custom .carousel-indicators li {
background-color: transparent;
-webkit-border-radius: 0;
border-radius: 0;
display: inline-block;
height: auto;
margin: 0 !important;
width: auto;
}
#carousel-custom .carousel-indicators li img {
display: block;
opacity: 0.5;
}
#carousel-custom .carousel-indicators li.active img {
opacity: 1;
}
#carousel-custom .carousel-indicators li:hover img {
opacity: 0.75;
}