wrap using pure js

HTML

<div class="af-button-group af-button-group-justified">
    <button class="af-button af-button-lg af-button-danger">sds</button>
    <div>sdsasas</div>
    <button class="af-button af-button-lg">sds</button>
</div>

CSS

.gp {
    background: blue;
    padding: 8px;
}

JavaScript

function fixjsf() {
    var parent = document.getElementsByClassName("af-button-group-justified");
    var elementsCount = parent.length;
    for (var i = 0; i < elementsCount; i++) {
        var childCount = parent[i].childNodes.length;

        var elementContent = "";
        for (var j = 0; j < childCount; j++) {           
            if (parent[i].childNodes[j].nodeName == "BUTTON") {
                var clone = parent[i].childNodes[j].outerHTML;
                elementContent += "<div class='gp'>" + clone + "</div>";
            }



        }
        parent[i].innerHTML = elementContent;

    }
}

fixjsf();