SOURCE

<div class="container">
  <header class='sticky-top'> 
    <nav class="navbar navbar-expand-lg navbar-light bg-light">
      <a class="navbar-brand" href="#">Navbar</a>
        <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarNav" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
        <span class="navbar-toggler-icon"></span>
      </button>
      <div class="collapse navbar-collapse" id="navbarNav">
        <ul class="navbar-nav">
          <li class="nav-item active">
            <a class="nav-link" href="#home">Home <span class="sr-only">(current)</span></a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#feature">Features</a>
          </li>
          <li class="nav-item">
            <a class="nav-link" href="#pricing">Pricing</a>
          </li>
          <li class="nav-item">
            <a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
          </li>
        </ul>
      </div>
    </nav>
  </header>
  
  <div id='home' class='homeClass text-center'>
    <span>HomePage</span>
  </div>
  <div id='feature' class='featureClass text-center'>
    <span>FeaturePage</span>
  </div>
  <div id='pricing' class='pricingClass text-center'>
    <span>PricingPage</span>
  </div>
  <div class='footer text-center'>
    <span>footer</span>
  </div>
</div>

.bd-navbar {
  position: sticky;
  top: 0;
  z-index: 1071;
}

.homeClass {
  height: 300px;
  width: 100%;
  background-color: pink
}

.featureClass {
  height: 500px;
  width: 100%;
  background-color: #563d7c
}

.pricingClass {
  height: 400px;
  width: 100%;
  background-color: blue
}

.footer {
  height: 100px;
  width: 100%;
  background-color: #808080
}