JSFiddle - React, Tailwind, and code Playground
HTML
<div class="form_line">
<div class="column-50">
<div class="line_desc">
Data Início<font>*</font>
</div>
<div class="line_field">
<div class="form-group">
<input id="datepicker1" class="form-control input date-check check-date" placeholder="Data Início - DD-MM-YYYY" type="text" name="event_date_start">
</div>
</div>
</div>
<div class="column-50">
<div class="line_desc">
Data Fim<font>*</font>
</div>
<div class="line_field">
<div class="form-group">
<input id="datepicker2" class="form-control input date-check check-date2" placeholder="Data Fim - DD-MM-YYYY" type="text" name="event_date_end">
</div>
</div>
</div>
</div>
JavaScript
$(".check-date").on("change", function() {
checkIfSecondDateIsGreaterThanFirst(this);
});
function checkIfSecondDateIsGreaterThanFirst(date) {
var next_date = $(date).closest('.column-50').next().find('.check-date2');
alert($(next_date).val('class'));
}