Ссылка для getSiblings part.
document.onclick = e => {
var siblings = getSiblings(e.target.parentElement);
siblings.forEach(element => {
var children = element.querySelectorAll(".children");
children.forEach(el => {
el.classList.add("unselected");
})
})
}
var getSiblings = function(elem) {
// Setup siblings array and get the first sibling
var siblings = [];
var sibling = elem.parentNode.firstChild;
// Loop through each sibling and push to the array
while (sibling) {
if (sibling.nodeType === 1 && sibling !== elem) {
siblings.push(sibling);
}
sibling = sibling.nextSibling
}
return siblings;
};
.unselected {
color: red
}
<div>siblings div
<div>CLICK HERE</div>
</div>
<div>siblings div2
<div>OR CLICK HERE</div>
</div>
<div>siblings div3
<div class="children">div with class children</div>
</div>
<div>siblings div4
<div>OR CLICK HERE</div>
</div>