Filter not working when inside <ion-nav-buttons>

Hello guys, I really need my filter to be in my <ion-nav-buttons> , but the following code isn’t working

<ion-nav-buttons side="right">

  <div class="bar bar-header search-bar">
    <div class="item-input-wrapper">
    <input type="search" placeholder="Search" ng-model="filter">
    </div>
  </div>

</ion-nav-buttons>

<ion-content>
  <ion-list>
    <ion-item ng-repeat="post in postscope | filter:filter" class="item">

	      <h2 ng-bind-html="(post.title)"></h2>

    </ion-item>
  </ion-list>
</ion-content>

Thanks!

Does the solution in this topic help?