JSFiddle - React, Tailwind, and code Playground

HTML

<p>
  <label>Arrive</label>
  <input id="from-date1" class="from-date calender" type="text" />
</p>

<p>
  <label>Depart</label>
  <input id="to-date1" class="to-date calender" type="text" />
</p>

<p>
  <label>Arrive</label>
  <input id="from-date2" class="from-date calender" type="text" />
</p>

<p>
  <label>Depart</label>
  <input id="to-date2" class="to-date calender" type="text" />
</p>

JavaScript

function nextInDOM(_selector, _subject) {
    var next = getNext(_subject);
    while(next.length != 0) {
        var found = searchFor(_selector, next);
        if(found != null) return found;
        next = getNext(next);
    }
    return null;
}
function getNext(_subject) {
    if(_subject.next().length > 0) return _subject.next();
    return getNext(_subject.parent());
}
function searchFor(_selector, _subject) {
    if(_subject.is(_selector)) return _subject;
    else {
        var found = null;
        _subject.children().each(function() {
            found = searchFor(_selector, $(this));
            if(found != null) return false;
        });
        return found;
    }
    return null; // will/should never get here
}

var n = nextInDOM('.from-date', $('.from-date').first());
if(n != null) n.css('border', '1px solid red');