<ul>
  <li>
    <span>Текст, текст, текст</span>
    <span></span>
    <span>52891</span>
  </li>
  <li>
    <span>Текст</span>
    <span></span>
    <span>11</span>
  </li>
  <li>
    <span>Текст, текст</span>
    <span></span>
    <span>13517384</span>
  </li>
</ul>

li {
  list-style: none;
  display: flex;
  justify-content: space-between;
}
li span:nth-child(2) {
  flex: 1 0;
  border-bottom: 1px dotted #000;
  height: 1em;
  margin: 0 .4em;
}