JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wysibb-toolbar">
    <div class="wysibb-toolbar-container">Div1</div>
    <div class="wysibb-toolbar-container">Div2</div>
    <div class="wysibb-toolbar-container">//(This is to be made display:none)
        <div class="wysibb-toolbar-btn wbb-code" jQuery110208619481903000815="71">Div31</div>
        <div class="wysibb-toolbar-btn wbb-code" jQuery110208619481903000815="71">Div32</div>
    </div>
</div>

CSS

.wysibb-toolbar-container:last-child {
    display:none;
}