JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/ui-lightness/jquery-ui.css">
<div id="one">
    <div class="two">
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
        <div class="entry">
            Content here
        </div>
    </div>
</div>

CSS

.two > div {
    border: 1px solid blue;
    margin:4px;
}

JavaScript

var entries = $('#one > .two > div.entry');

entries.each(function(i) {
    if( i % 3 == 0 ) entries.slice(i,i+3).wrapAll('<div>');
});