<div class="wrapper">
    <ul>
        <li>
            <a class="active" href="#"><span>Link 1</span></a>
        </li>
        <li>
            <a href="#"><span>Link 2</span></a>
        </li>
        <li>
            <a href="#"><span>Link 3</span></a>
        </li>
        <li>
            <a href="#"><span>Linl 4</span></a>
        </li>
        <li>
            <a href="#"><span>Link 5</span></a>
        </li>
        <li>
            <a href="#"><span>Link 6</span></a>
        </li>
        <li>
            <a href="#"><span>Link 7</span></a>
        </li>
        <li>
            <a href="#"><span>Link 8</span></a>
        </li>
        <li>
            <a href="#"><span>Link 9</span></a>
        </li>
        <li>
            <a href="#"><span>Link 10</span></a>
        </li>
    </ul>
    <span class="js-status-menu status-menu"></span>
</div>

div {
  max-width: 277px;
  height: 100%;
  background: #333;
  text-align: left;
  padding: 0;
  position: relative;
}

ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

ul li a {
    display: block;
    text-decoration: none;
    font-size: 12px;
    line-height: 1.25em;
    color: #fff;
    border-bottom: solid 1px #333D4A;
    padding: 14px 25px;
    position: relative;
}

ul li a:hover {
  color: #fff;
  background: #435162;
}

.status-menu {
    width: 5px;
    height: 43px;
    background: #4EFFFF;
    position: absolute;
    left: 0;
    top: 0;
}

$(document).ready(function() {
    if($('.js-status-menu').length){

        var jsMenuHover = $('.js-status-menu');
        var disclMenu = 0;

        var style = 'easeOutExpo';
        var default_top = Math.round($('ul li a.active').offset().top - $('ul').offset().top) + disclMenu;

        if($('ul li a.active').parents('.submenu').length){
            $('ul li a.active').parents('.submenu').show();
            $('ul li a.active').parents('.submenu').prev('a').addClass('open');
        }

        jsMenuHover.css({top: default_top});

        $('ul li a').hover(function () {
            var topPos = Math.round($(this).offset().top - $('ul').offset().top);
            $('.js-status-menu').stop(false, true).animate({top: topPos + disclMenu},{duration:500, easing: style});
        });

        $('ul').on('mouseleave',function () {
            if ($('ul li a').hasClass('active')){
                var default_top = Math.round($('ul li a.active').offset().top - $('ul').offset().top) + disclMenu;
            }
            jsMenuHover.stop(false, true).animate({top: default_top},{duration:500, easing: style});
        });

    }

});