Как вариант...
<!DOCTYPE html>
<html>
<head>
<script src='http://code.jquery.com/jquery-latest.js'></script>
<!--
<link rel='stylesheet type=text/css href=tmp.css' />
-->
<style type='text/css'>
.activ_click {
color: red;
}
.in_compl {
background-color: yellow;
}
</style>
<script type='text/javascript'>
$(function (){
$('.active-result').click(function (){
$(this).toggleClass('activ_click');
var ob=$(this).parents('.chosen-container');
var o=ob.find('.chosen-single');
if (ob.find('.active-result').hasClass('activ_click')) {
o.addClass('in_compl');
} else {
o.removeClass('in_compl');
};
});
});
</script>
</head>
<body>
<div class="chosen-container">
<a class="chosen-single">
<span>Указать</span>
</a>
<div class="chosen-drop">
<ul class="chosen-results">
<li class="active-result">пункт 1</li>
<li class="active-result">пункт 2</li>
<li class="active-result">пункт 3</li>
<li class="active-result">пункт 4</li>
</ul>
</div>
</div>
<div class="chosen-container">
<a class="chosen-single">
<span>Указать</span>
</a>
<div class="chosen-drop">
<ul class="chosen-results">
<li class="active-result">пункт 1</li>
<li class="active-result">пункт 2</li>
<li class="active-result">пункт 3</li>
<li class="active-result">пункт 4</li>
</ul>
</div>
</div>
</body>
</html>