JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block">text 2<div class="block2">text</div></div>

CSS

.block {
  position: relative;
  
  width: 300px;
  height: 100px;
  
  background: #ffffff;
  border: 5px solid black;
  
  z-index: 1;
}

.block2 {
  position: absolute;
  top: 0;
  right: -5px;
  
  width: 100px;
  height: 150px;
  
  background: #ffffff;
  border: 5px solid black;
  border-top: 0px solid #ffffff;
  
  z-index: 2;
}

.block2:before{
  content: '';
  height: 100px;
  width: 5px;
  background: #fff;
  position: absolute;
  top: 0px;
  left: -5px;
  display: block;
}