Tipylja,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.middleMenu__block--hidden{
display: none;
}
</style>
<script>
window.addEventListener("load", function(e) {
var control = document.querySelector(".middleMenu__control");
var menuBlock = document.querySelector(".middleMenu__block");
document.addEventListener("click", function(e) {
if (control === e.target) {
e.preventDefault();
menuBlock.classList.toggle("middleMenu__block--hidden")
} else if (e.target.closest(".middleMenu__block") || menuBlock.classList.contains("middleMenu__block--hidden")) return;
else menuBlock.classList.add("middleMenu__block--hidden")
}, true)
});
</script>
</head>
<body>
<nav class="middleMenu layout__middleMenu">
<a href="#" class="middleMenu__control">Каталог товаров</a>
<ul class="middleMenu__block middleMenu__block--hidden">
<li class="middleMenu__item">
<a href="#" class="middleMenu__link">Двери</a>
</li>
<li class="middleMenu__item">
<a href="#" class="middleMenu__link">Карнизы</a>
</li>
</ul>
</nav>
</body>
</html>