title: Remove Options from Bootstrap-Select when Proceeding Select Changes
body: <p>I have tried multiple combinations and just can't clear this control.
  I am using jquery 3.2.1, the control is Bootstrap-select v1.13.1 here is the link
  <a href="https://developer.snapappointments.com/bootstrap-select/" rel="nofollow noreferrer">https://developer.snapappointments.com/bootstrap-select/</a>.</p>
  
  <p>I want to clear the teamPositionFilter options which is multi-select whenever the 
  groupFilter before it changes. Right now it is appending values after each change. I can step through the javascript code but it does not change the list.</p>
  
  <pre><code>@Html.DropDownList("groupFilter", (SelectList)(@ViewBag.GroupList), new { @class = "singleselectpicker col-md-3", title = "Group:", data_header = "Select Group:" })
  @Html.DropDownList("teamPositionFilter", (MultiSelectList)(@ViewBag.TeamPositionList), new { @class = "multiselectpicker col-md-3", multiple = "multiple", title = "Team Position:", data_header = "Select one or more Team Positions:" })
  
  $(function() {
  
  $('#groupFilter').change(function () {
      var #teamPositionFilter = $('#teamPositionFilter');
      #teamPositionFilter.find('option').remove();
      #teamPositionFilter.selectpicker('refresh');
  });
  
  
  $('.singleselectpicker').selectpicker({
      showTick: true,
      tickIcon: 'glyphicon-pushpin',
      liveSearch: true,
      liveSearchStyle: 'contains',
      selectOnTab: true,
      showContent: true,
      size: 10,
      width: 'false'
  });
  
  $('.multiselectpicker').selectpicker({
          actionsBox: true,
          selectAllText: 'Select All',
          deselectAllText: 'Deselect All',
          selectedTextFormat: 'count',
          showTick: true,
          tickIcon: 'glyphicon-pushpin',
          liveSearch: true,
          liveSearchStyle: 'contains',
          selectOnTab: true,
          showContent: true,
          size: 10,
          width: 'false',
          multipleSeparator: ', '
  });
  </code></pre>
  
  <p>});</p>