how to set value select2
$('#sel_users').select2().trigger('change');
$(document).ready(function(){
  // Initialize Select2
  $('#sel_users').select2();
  // Set option selected onchange
  $('#user_selected').change(function(){
    var value = $(this).val();
    // Set selected 
    $('#sel_users').val(value);
    $('#sel_users').select2().trigger('change');
  });
});
