Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/1.0.8/angular.min.js"></script>
<div ng-controller="MyCtrl">
  <input type="text" placeholder="Nome do usuário" ng-model="search_nome">
  <select ng-model="search_turmas.turmas.value">
    <option value="!!">Todos</option>
    <option ng-repeat="option in listTurmasFilter" value="{{option.value}}">{{option.title}}</option>
  </select>
  <table>
    <thead>
      <tr>
        <th>ID</th>
        <th>Nome</th>
        <th>Turmas</th>
      </tr>
    </thead>
    <tbody>
      <tr ng-repeat="usuario in dadosUserAndTurma | filter:{nome:search_nome} | filter:filterTurma">
        <td>{{usuario.idUser}}</td>
        <td>{{usuario.nome}}</td>
        <td><span ng-repeat="trm in usuario.turmas">
                             &nbsp;[ {{trm.turma}} ]&nbsp;
                     </span></td>
      </tr>
    </tbody>
  </table>
</div>

CSS

thead th {
  font-weight: bold;
  height: 40px;
}

JavaScript

function MyCtrl($scope) {

  $scope.listTurmasFilter = [{
    title: "Turma 1",
    value: 1
  }, {
    title: "Turma 2",
    value: 2
  }, {
    title: "Turma 3",
    value: 3
  }];

  $scope.search_nome = "";

  $scope.search_turmas = {
    turmas: {
      value: "!!"
    }
  };

    $scope.filterTurma = function(usuario) {
      if ($scope.search_turmas.turmas.value == '!!')
        return true;
      for (var i = 0; i < usuario.turmas.length; i++) {
        var turma = usuario.turmas[i];
        console.log('Usuário: ' + usuario.nome);
        console.log('Turma usuário: ' + turma.value);
        console.log('Turma filtrada: ' + $scope.search_turmas.turmas.value);
        if (turma.value == $scope.search_turmas.turmas.value)
          return true;
      }
      return false;
    };

  $scope.dadosUserAndTurma = [{
    idUser: 20,
    nome: "Carlos",
    turmas: [{
      turma: "Turma 1",
      value: 1
    }, {
      turma: "Turma 2",
      value: 2
    }, {
      turma: "Turma 3",
      value: 3
    }]
  }, {
    idUser: 21,
    nome: "Luiz",
    turmas: [{
      turma: "Turma 1",
      value: 1
    }, {
      turma: "Turma 3",
      value: 3
    }]
  }, {
    idUser: 22,
    nome: "Priscilla",
    turmas: [{
      turma: "Turma 2",
      value: 2
    }]
  }, {
    idUser: 24,
    nome: "Pedro",
    turmas: []
  }];

}