var app = angular.module('plunker', []);

app.controller('MainCtrl', function($scope) {
  
  $scope.workspaces = [
    {name: "Bar", id: "1"},
    {name: "Service", id: "2"},
    {name: "Cleaning", id: "3"}
  ]
  
  $scope.workspaces2 = [
    {name: "Cleaning", id: "3"},
    {name: "Service", id: "2"}
  ]
  
  $scope.employees = [
      {name:"Harald", workspaces:[{id:"1"}, {id:"2"}]},
      {name:"Peter", workspaces:[{id:"2"}, {id:"1"}, {id:"3"}]},
      {name:"Eugen", workspaces:[{id:"3"}], different:[{id:"1"}]}
    ]
});
<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="style.css" />
    <script data-require="angular.js@1.2.x" src="http://code.angularjs.org/1.2.8/angular.js" data-semver="1.2.8"></script>
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
  
    <div ng-repeat="workspace in workspaces">
      <input type="radio" ng-model="$parent.filtering.workspaces" value="{{workspace.id}}">{{workspace}}</input>
    </div><br>
    <div ng-repeat="workspace in workspaces2">
      <input type="radio" ng-model="$parent.filtering.workspaces" value="{{workspace.id}}">{{workspace}}</input>
    </div>
    
    <p>Debug Search Object: {{filtering}}</p>
  
  <ul title="Employees">
     <li ng-repeat="e in employees | filter:filtering">{{e}}</il>
  </ul>
  </body>

</html>
/* Put your css in here */