Hovering over a menu item to highlight background of subnav - css

Question

I'm trying to make it so when you hover over one of the categories in the header nav "CALLS | CHATS | MORE" the subnav below shows and the ul that is associated with the header nav changes its background color i know i can just add a class using jQuery but could i not do this with a sibling selector or something? i just think my HTML is layed out incorrectly at the moment for it to work TIA. this is what i currently have.
<header class="header">
<ul class="header__nav">
<li class="header__navItem header__navItem--calls">Calls</li>
<li class="header__navItem header__navItem--chats">Chats</li>
<li class="header__navItem header__navItem--more">More</li>
</ul>
<nav class="navigation">
<div class="navigation__wrapper cf">
<ul class="navItems navItems--calls">
<li class="navItems__item"></li>
<li class="navItems__item"></li>
<li class="navItems__item"></li>
<li class="navItems__item"></li>
<div class="bgHover"></div>
</ul>
</div>
</nav>
</header>
.header {
height: 5.8rem;
background: rgba(25, 25, 25, 0.9);
position: absolute;
width: 100%;
z-index: 999;
&__nav {
display: inline-block;
text-align: center;
font-size: 0;
left: 50%;
position: absolute;
transform: translateX(-50%);
padding: 0;
margin: 0;
}
&__navItem {
color: $white;
display: inline-block;
#include font-size(18);
padding: 0 4rem;
line-height: 5.8rem;
letter-spacing: 0.1rem;
position: relative;
cursor: default;
font-weight: 400;
text-transform: uppercase;
font-family: $lato;
&--calls {
&:hover ~ .navigation__wrapper .navItems .bgHover {
max-height: 35rem;
}
&:hover {
color: red;
}
}
}

Answer 1

I'm presuming you want the submenu to appear below the header nav. If so, then move your sub nav into the li tag for the corresponding header item, like so:
<li class="header__navItem header__navItem--calls">Calls
<ul class="navItems navItems--calls">
<li class="navItems__item">First</li>
<li class="navItems__item">Second</li>
<li class="navItems__item">Third</li>
<li class="navItems__item">Fourth</li>
</ul>
</li>