Horizontal scrollable div's in a bootstrap row

Please check. Is it what you want to achieve?

horizontal scrolling

CodePen  •  JSFiddle

/* The heart of the matter */
.testimonial-group > .row {
  overflow-x: auto;
  white-space: nowrap;
}
.testimonial-group > .row > .col-xs-4 {
  display: inline-block;
  float: none;
}

/* Decorations */
.col-xs-4 { color: #fff; font-size: 48px; padding-bottom: 20px; padding-top: 18px; }
.col-xs-4:nth-child(3n+1) { background: #c69; }
.col-xs-4:nth-child(3n+2) { background: #9c6; }
.col-xs-4:nth-child(3n+3) { background: #69c; }
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

<div class="container testimonial-group">
  <div class="row text-center">
    <div class="col-xs-4">1</div><!--
 --><div class="col-xs-4">2</div><!--
 --><div class="col-xs-4">3</div><!--
 --><div class="col-xs-4">4</div><!--
 --><div class="col-xs-4">5</div><!--
 --><div class="col-xs-4">6</div><!--
 --><div class="col-xs-4">7</div><!--
 --><div class="col-xs-4">8</div><!--
 --><div class="col-xs-4">9</div>
  </div>
</div>

for Bootstrap 4

Thanks Hector for the comment!

https://codepen.io/glebkema/pen/xxOgaMm

/* The heart of the matter */
.testimonial-group > .row {
  display: block;
  overflow-x: auto;
  white-space: nowrap;
}
.testimonial-group > .row > .col-4 {
  display: inline-block;
}

/* Decorations */
.col-4 { color: #fff; font-size: 48px; padding-bottom: 20px; padding-top: 18px; }
.col-4:nth-child(3n+1) { background: #c69; }
.col-4:nth-child(3n+2) { background: #9c6; }
.col-4:nth-child(3n+3) { background: #69c; }
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.min.css">

<div class="container testimonial-group">
  <div class="row text-center">
    <div class="col-4">1</div><!--
 --><div class="col-4">2</div><!--
 --><div class="col-4">3</div><!--
 --><div class="col-4">4</div><!--
 --><div class="col-4">5</div><!--
 --><div class="col-4">6</div><!--
 --><div class="col-4">7</div><!--
 --><div class="col-4">8</div><!--
 --><div class="col-4">9</div>
  </div>
</div>


In Bootstrap 4 you will need to add

flex-wrap: nowrap;

to

.testimonial-group > .row

in addition to Gleb's answer


The Flexbox Method

/* The heart of the matter */
.testimonial-group > .row {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
}
.testimonial-group > .row > .col-xs-4 {
  flex: 0 0 auto;
}

/* Decorations */
.col-xs-4 { color: #fff; font-size: 48px; padding-bottom: 20px; padding-top: 18px; }
.col-xs-4:nth-child(3n+1) { background: #c69; }
.col-xs-4:nth-child(3n+2) { background: #9c6; }
.col-xs-4:nth-child(3n+3) { background: #69c; }
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

<div class="container testimonial-group">
  <div class="row text-center">
    <div class="col-xs-4">1</div><!--
 --><div class="col-xs-4">2</div><!--
 --><div class="col-xs-4">3</div><!--
 --><div class="col-xs-4">4</div><!--
 --><div class="col-xs-4">5</div><!--
 --><div class="col-xs-4">6</div><!--
 --><div class="col-xs-4">7</div><!--
 --><div class="col-xs-4">8</div><!--
 --><div class="col-xs-4">9</div>
  </div>
</div>