FontAwesome Icons in Dropdown Nav

Hey everybody.  Need to pick your brain.  So I am trying to have custom icons in a site's dropdown menu.  I have this figured out, kind of...  The problem is, the code I am using, puts these icons in all of my drop-down (this site has 2).  I really want these icons in just one dropdown, as they don't make sense in the other. I  understand why it's putting these icons in all of my dropdowns, but I don't know how to isolate it to just one.  I will paste the code I am using below.  Thanks for any help!

Code:

.header-nav-folder-item:nth-child(1) a::before
{
content: '\f0c8';
font-family: FontAwesome;
display: inline-block;
padding-right: 9px;
color: #0D4982;
}

.header-nav-folder-item:nth-child(2) a::before
{
content: '\f0c8';
font-family: FontAwesome;
display: inline-block;
padding-right: 9px;
color: #A0211F
}

.header-nav-folder-item:nth-child(3) a::before
{
content: '\f0c8';
font-family: FontAwesome;
display: inline-block;
padding-right: 9px;
color: #FCB90B
}

I think I got this sorted.  I used this code and customized as needed:

.header-nav-item:nth-child(1) {
.header-nav-folder-item:nth-child(1) a::before
{
content: '\f0c8';
font-family: FontAwesome;
display: inline-block;
padding-right: 9px;
color: #0D4982;
}