Filter combobox search Angularjs

Question

I have the SELECT multiple with options for query, only when selecting an item does not return anything, if someone can give a strength I thank you.

/* Retorna operadoras */
$scope.operadoras = [{
    nome: "CLARO"
  },
  {
    nome: "TIM"
  },
  {
    nome: "VIVO"
  },
  {
    nome: "OI"
  },
  {
    nome: "NEXTEL"
  }
];

$scope.filtroOperadora = function() {
  return ($scope.operadoras == busca.nome);
}

<div class="form-group col-md-2 input-group-sm mb-3">
  <label for="exampleInputPassword1" class="text-sm font-weight-bold">Operadora</label>
  <select class="form-control seleciona text-sm" multiple name="prospectOperadora" data-width="100%" ng-model="busca">
    <option value="">Selecione</option>
    <option ng-repeat="oper in operadoras" value="{{oper.nome}}">
      {{oper.nome}}
    </option>
  </select>
</div>

<li style="font-size: 13px; padding:10px;" ng-repeat="prospect in listaProspect | orderBy: 'prospectNome' | betweenDate:'prospeccaoPrevisao':startDate:endDate | filter:busca track by $index">
</li>

Answer 1

I decided to create an example, where the grouping of information is made a filter in the SELECT with the property multiple:

var app = angular.module('app', []);
app.controller('ctrl', function($scope) {
  $scope.operadora = [];
  $scope.operadoras = [{
      nome: "CLARO"
    },
    {
      nome: "TIM"
    },
    {
      nome: "VIVO"
    },
    {
      nome: "OI"
    },
    {
      nome: "NEXTEL"
    }
  ];

  $scope.lista = [{
      nome: 'item 1',
      operadora: 'OI'
    },
    {
      nome: 'item 2',
      operadora: 'OI'
    },
    {
      nome: 'item 3',
      operadora: 'CLARO'
    },
    {
      nome: 'item 4',
      operadora: 'NEXTEL'
    },
    {
      nome: 'item 5',
      operadora: 'VIVO'
    },
    {
      nome: 'item 6',
      operadora: 'TIM'
    }
  ];

  $scope.listFilter = function(model) {    
    if ($scope.operadora.length == 0) return true;
    return $scope.operadora.indexOf(model.operadora) > -1;
  };
});

<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/css/bootstrap-select.min.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.12.4/js/bootstrap-select.min.js"></script>

<div ng-app="app" ng-controller="ctrl">
  <select multiple ng-model="operadora" class="selectpicker">
    <option ng-repeat="o in operadoras" value="{{o.nome}}">{{o.nome}}</option>
  </select>
  <br /><br /><br />
  <ul>
    <li ng-repeat="i in lista  | filter:listFilter">
      {{i.nome}} {{i.operadora}}
    </li>
  </ul>
</div>

In that case you need to create a custom filter, and search the array of information the items that were selected in the SELECT which is another array also.

_References:

• Filter date in en format in Angularjs?
• Date angle filter with mask 'dd/MM/yyyy HH:mm:ss'
• API Reference ng filter Components in ng date
• Angular Series: The filter, ng-model, ng-repeat and a few more things...
• Angularjs Series - Using Filter with search

Answer 2

By the code informed, it is not possible to conclude much.

But for what you put here:

$scope.filtroOperadora = function() {
  return ($scope.operadoras == busca.nome);
}

It doesn’t make much sense, since the $Scope.operators is an Array and name search. is probably a string.

I made a basic example here: https://next.plnkr.co/edit/Q1pKm1iN0P102c23

However, as you can probably have an array of strings you want to search inside the list of operators, goes another example: https://next.plnkr.co/edit/LoV5i3g6byeERHWo

Abs.