JSFiddle - React, Tailwind, and code Playground

HTML

<div class="list">
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_3">
      <div class="title">2. Текст 2</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_3">
      <div class="title">2. Текст 2</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_2">
      <div class="title">1. Текст</div>
   </div>
   <div class="line_5">
      <div class="title">4. Текст 3</div>
   </div>
   <div class="line_5">
      <div class="title">4. Текст 3</div>
   </div>
</div>

CSS

.list > div {
  background: #eee;
  height: 20px;
  border-bottom: 1px solid #ccc;
}

.title {
  display: none;
}

JavaScript

document.querySelectorAll('.list div:not(.title)').forEach(div => {
	document.querySelector(`.list .${div.className} .title`).style.display = 'block';
});