Backround из 3х частей

.block { 
  position: relative; 
  height: 100vh; 
  background-color: #ccc; 
  background-image: url(https://www.nature-guide.info/images/website/promobalk.png), url(https://www.nature-guide.info/images/website/promobalk.png); 
  background-position: center top, center bottom; 
  background-repeat: no-repeat, no-repeat; 
} 
 
.block:after { 
  content: ''; 
  z-index: 1; 
  position: absolute; 
  top: 100px; 
  left: 0; 
  width: 100%; 
  height: calc(100vh - 200px); 
  background: url(http://naturalcrooks.com/rambles/wp-content/uploads/2013/11/NewNaturalCrooksHeaderImage.jpg) center top repeat-y; 
}

<div class="block"></div>

.block { 
  width: 500px; 
  height: 500px; 
} 
.block > div { 
  height: 33%; 
} 
.top { 
  background: red; 
} 
.center { 
    background: #e4ff00; 
} 
.bottom { 
  background: #008800; 
}

<div class="block"> 
    <div class="top"></div> 
    <div class="center "></div> 
    <div class="bottom"></div> 
</div>