Capture which li a class is attached to - sass

Question

I am not sure if this is possible, but is there a way for sass to identify which li a particular class is attached to?
If I had:
<ul>
<li></li>
<li></li>
<li class="Selected"></li>
<li></li>
<li></li>
</ul>
And I'm trying to get a mixin to switch a CSS property based on where the "Selected" class is located. So something like:
ul li { background: url(#include(mixin)); }
$Names:("../Images/One.png","../Images/Two.png","../Images/Three.png","../Images/Four.png","../Images/Five.png",)
#include mixin($Names){
#each $liindex in $Names{
$i: index($Names, $liindex );
if(/* see if this li has class Selected */){
/* change property here?
}
}
}

Answer 1

This should be doable with nth-of-type. Something like this:
#mixin bg-mixin($Names){
#each $bg-url in $Names{
$i: index($Names, $bg-url );
&:nth-of-type(#{$i}).Selected { background: url($bg-url); }
}
}
and used like this:
ul li {
#include bg-mixin($Names);
}
resulting in
ul li:nth-of-type(1).Selected {
background: url("../Images/One.png");
}
ul li:nth-of-type(2).Selected {
background: url("../Images/Two.png");
}
ul li:nth-of-type(3).Selected {
background: url("../Images/Three.png");
}
ul li:nth-of-type(4).Selected {
background: url("../Images/Four.png");
}
ul li:nth-of-type(5).Selected {
background: url("../Images/Five.png");
}