JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<div class="mydiv" data-i="1" data-j="2">
    <span class="mydiv_span" data-one="one" data-two="two">TEXT</span>
</div>

<div class="mydiv" data-i="2" data-j="1">
    <span class="mydiv_span" data-one="one" data-two="two">TEXT</span>
</div>

JavaScript

var i,j;
// i=1;
// j=2;
var span = $('[data-i=1][data-j=2]')[0].children[0];
span.dataset.one = '';
span.dataset.two = '';
$(span).text('qwe');
// ...