<!-- we could keep `block__element-3` as a sub element... -->
<div class="block">
<div class="block__element-1">
<div class="block__element-3"></div>
</div>
<div class="block__element-2"></div>
</div>
<!-- or we could convert `block__element-3` into a new block... -->
<div class="block">
<div class="block__element-1">
<div class="new-block"></div>
</div>
<div class="block__element-2"></div>
</div>