JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="arrow"></div>
  <div class="arrow"></div>
</div>

CSS

body{
  background-color: #DCDCDC;
}
.container {
  width: 50%;
  height: 7%;
  background: white;
  border-radius: 20px;
  position: absolute;
}
.arrow {
  background: green;
  border-radius: 20px;
  height: 100%;
  position: absolute;
}
.arrow:after{
  content: "";
  display: block;
  padding-right: 100%;
}
.arrow:last-child {
  right: 0;
}