JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
<li class="list">
    liste1
</li>
<li class="data">
    <div class="mes_datas">
        <span class="list-type">T1</span>
        <span class="list-value">30000</span>
    </div>
</li>
<li class="data">
    <div class="mes_datas">
        <span class="list-type">T2</span>
        <span class="list-value">25444</span>
    </div>
</li>
<li class="list">
    liste2 
</li>
<li class="data">
    <div class="mes_datas">
        <span class="list-type">T5</span>
        <span class="list-value">300030</span>
    </div>
</li>
<li class="data">
    <div class="mes_datas">
        <span class="list-type">T6</span>
        <span class="list-value">2543344</span>
    </div>
</li>
</ul>

JavaScript

$('.data').on('click', function(){
   alert($(this).prevAll('.list').html() )

})