Making a single {{link}} active in Ember

In my Ember app I have navigation bar with groups. Each unique item appears twice in the bar: in its own group and in "All Items" group:

If user selects Item 3 both links become active by getting active CSS class:

How can I change my code so that the link that user has clicked on becomes active? If user opens /item/3 URL manually the first link only should be active.

Here is my code so far: http://ift.tt/1pZ5yfC

var App = Ember.Application.create({
  rootElement: '#app'
});

App.Router.map(function() {
  this.route('item', { path: '/item/:item_id' });
});

App.ItemRoute = Ember.Route.extend({
  model: function(params) {
    return params.item_id;  
  }
});

Navigation bar template:

<ul>
  <li>{{#link-to "index"}}Index{{/link-to}}</li>
  <li>
    All items
    <ul>
      <li>{{#link-to "item" 1}}Item 1{{/link-to}}</li>
      <li>{{#link-to "item" 2}}Item 2{{/link-to}}</li>
      <li>{{#link-to "item" 3}}Item 3{{/link-to}}</li>
      <li>{{#link-to "item" 4}}Item 4{{/link-to}}</li>
      <li>{{#link-to "item" 5}}Item 5{{/link-to}}</li>
    </ul>
  </li>
  <li>
    Group A
    <ul>
      <li>{{#link-to "item" 1}}Item 1{{/link-to}}</li>
      <li>{{#link-to "item" 2}}Item 2{{/link-to}}</li>
      <li>{{#link-to "item" 3}}Item 3{{/link-to}}</li>
    </ul>
  </li>
  <li>
    Group B
    <ul>
      <li>{{#link-to "item" 4}}Item 4{{/link-to}}</li>
      <li>{{#link-to "item" 5}}Item 5{{/link-to}}</li>
    </ul>
  </li>
</ul>
<hr />

{{outlet}}

Ember version: 2.4.2