jQuery
$el.siblings();
Native - latest, Edge13+
[...el.parentNode.children].filter((child) =>
child !== el
);
Native (alternative) - latest, Edge13+
Array.from(el.parentNode.children).filter((child) =>
child !== el
);
Native - IE10+
Array.prototype.filter.call(el.parentNode.children, (child) =>
child !== el
);