{{funcionarios|json}}

HTML

<div class="form-group">
  <label>Funcionarios: </label>
  <ui-multi-select placeholder="Buscar..."
                   close-on-select-item="false"
                   ng-model="funcionarios"
                   tagging="addItem(value)"
                   tagging-model="items">
    <ui-multi-select-item ng-repeat="item in funcionarios"
                          ng-value="item">
      {{item.nome}}
    </ui-multi-select-item>
    <ui-multi-select-option ng-repeat="option in items"
                            ng-value="option">
      {{option.nome}}
    </ui-multi-select-option>
  </ui-multi-select>
</div>

JavaScript

angular.module('app', ['ngUiMultiSelect'])
.controller('ctrl', function($scope, $timeout){

    $scope.addItem = function(value){
        return {nome: value};
    }

    $scope.items = [
      { nome: 'Mateus',  idade: 20},
      { nome: 'Willian', idade: 25},
      { nome: 'Felipe',  idade: 25},
      { nome: 'Munif',   idade: 50}
    ];

})