JSFiddle - React, Tailwind, and code Playground

HTML

<div class="field--item">
<div class="banner-field">

  <div class="banner-field">
  
    <div class="field--item">
    
      <div class="banner-wrap">
          <span>Banner 1</span>
          <div id="button">
            button
          </div>
      </div>
      
    </div>
    
    <div class="field--item">
    
      <div class="banner-wrap">
          <span>Banner 2</span>
      </div>
      
    </div>
    
  </div>
</div>

</div>

<div class="field--item">
    <div class="boom">BOOM</div>  
</div>

<br/><br/><br/>

<span>Selected</span>
<ul id="results"></ul>

CSS

.field--item{border: 1px solid red; margin: 10px;}

JavaScript

var start = $("#button");
var end = start.parent('div').last();

start.on('click', function(){
	end.css( "background-color", "rgba(220,220,220,0.9)" );
})