JSFiddle - React, Tailwind, and code Playground

HTML

<div class="super-block">
  <div class="block"></div>
  <div class="block-inner"></div>
</div>

SCSS

* {
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
}

.super-block {
  width: 480px;
  height: 180px;
  position: relative;
  margin: 40px;
}

.block {
  width: 100%;
  height: 100%;
  border: 2px solid #e0e0e0;
  position: relative;
  background-color: #fff;
  z-index: 4;
  &:before {
    content: '';
    position: absolute;
    top: 33%;
    left: -2px;
    margin-top: -6px;
    background-color: #fff;
    height: 13px;
    width: 2px;
  }
}

.block-inner {
  position: absolute;
  top: 33%;
  left: -17px;
  margin-top: -10px;
  width: 17px;
  height: 17px;
  z-index: 3;
  border-radius: 0 0 0 100%;
  box-shadow: 0 0 0 2px #e0e0e0;
  &:before {
    content: '';
    position: absolute;
    width: 30px;
    height: 20px;
    -webkit-border-radius: 50%;
    -moz-border-radius: 50%;
    border-radius: 50%;
    background-color: #fff;
    border-bottom: 2px solid #e0e0e0;
    top: 1;
    margin-top: -16px;
    right: -11px;
  }
}