<div class="container">
  <div class="row">
    <div id="carousel" class="carousel slide" data-ride="carousel">
      <ol class="carousel-indicators">
        <li data-target="#carousel" data-slide-to="0" class="active"></li>
        <li data-target="#carousel" data-slide-to="1"></li>
      </ol>
      <div class="carousel-inner">
        <div class="carousel-item active">
          <div class="d-none d-lg-block">
            <div class="slide-box">
              <img src="https://picsum.photos/285/200/?image=0&random" alt="First slide">
              <img src="https://picsum.photos/285/200/?image=1&random" alt="First slide">
              <img src="https://picsum.photos/285/200/?image=2&random" alt="First slide">
              <img src="https://picsum.photos/285/200/?image=3&random" alt="First slide">
            </div>
          </div>
          <div class="d-none d-md-block d-lg-none">
            <div class="slide-box">
              <img src="https://picsum.photos/240/200/?image=0&random" alt="First slide">
              <img src="https://picsum.photos/240/200/?image=1&random" alt="First slide">
              <img src="https://picsum.photos/240/200/?image=2&random" alt="First slide">
            </div>
          </div>
          <div class="d-none d-sm-block d-md-none">
            <div class="slide-box">
              <img src="https://picsum.photos/270/200/?image=0&random" alt="First slide">
              <img src="https://picsum.photos/270/200/?image=1&random" alt="First slide">
            </div>
          </div>
          <div class="d-block d-sm-none">
            <img class="d-block w-100" src="https://picsum.photos/600/400/?image=0&random" alt="First slide">
          </div>
        </div>
        <div class="carousel-item">
          <div class="d-none d-lg-block">
            <div class="slide-box">
              <img src="https://picsum.photos/285/200/?image=4&random" alt="Second slide">
              <img src="https://picsum.photos/285/200/?image=5&random" alt="Second slide">
              <img src="https://picsum.photos/285/200/?image=6&random" alt="Second slide">
              <img src="https://picsum.photos/285/200/?image=7&random" alt="Second slide">
            </div>
          </div>
          <div class="d-none d-md-block d-lg-none">
            <div class="slide-box">
              <img src="https://picsum.photos/240/200/?image=3&random" alt="Second slide">
              <img src="https://picsum.photos/240/200/?image=4&random" alt="Second slide">
              <img src="https://picsum.photos/240/200/?image=5&random" alt="Second slide">
            </div>
          </div>
          <div class="d-none d-sm-block d-md-none">
            <div class="slide-box">
              <img src="https://picsum.photos/270/200/?image=2&random" alt="Second slide">
              <img src="https://picsum.photos/270/200/?image=3&random" alt="Second slide">
            </div>
          </div>
          <div class="d-block d-sm-none">
            <img class="d-block w-100" src="https://picsum.photos/600/400/?image=1&random" alt="Second slide">
          </div>
        </div>
      </div>
      <a class="carousel-control-prev" href="#carousel" role="button" data-slide="prev">
        <span class="carousel-control-prev-icon" aria-hidden="true"></span>
        <span class="sr-only">Previous</span>
      </a>
      <a class="carousel-control-next" href="#carousel" role="button" data-slide="next">
        <span class="carousel-control-next-icon" aria-hidden="true"></span>
        <span class="sr-only">Next</span>
      </a>
    </div>
  </div>
</div>

body {
    padding-top: 20px;
}

.carousel {
  width: 100%;
}

.slide-box {
  display: flex;
  justify-content: space-between;
}

@media (min-width: 576px) and (max-width: 767.98px) {
  .slide-box img {
    -ms-flex: 0 0 50%;
    flex: 0 0 50%;
    max-width: 50%;
  }
}

@media (min-width: 768px) and (max-width: 991.98px) {
  .slide-box img {
    -ms-flex: 0 0 33.3333%;
    flex: 0 0 33.3333%;
    max-width: 33.3333%;
  }
}

@media (min-width: 992px)
{
  .slide-box img {
    -ms-flex: 0 0 25%;
    flex: 0 0 25%;
    max-width: 25%;
  }
}

.carousel-caption {
  background-color: rgba(0, 0, 0, 0.5);
  padding: 20px;
  border-radius: .5rem;
}