title: Django REST Framework filter multiple fields
body: <blockquote>
    <p>Models</p>
  </blockquote>
  
  <pre><code>class Task(Model):
      employee_owner = ForeignKey(Employee, on_delete=CASCADE)
      employee_doer = ForeignKey(Employee, on_delete=CASCADE)
  </code></pre>
  
  <blockquote>
    <p>Views</p>
  </blockquote>
  
  <pre><code>class TaskViewSet(ModelViewSet):
      serializer_class = TaskSerializer
      queryset = Task.objects.all()
      filter_class = TaskFilter
  </code></pre>
  
  <blockquote>
    <p>Filter</p>
  </blockquote>
  
  <pre><code>class TaskFilter(FilterSet):
      owner_id = NumberFilter(name='employee_owner__id')
      doer_id = NumberFilter(name='employee_doer__id')
  
      class Meta:
          model = Task
          fields = {
              'owner_id',
              'doer_id'
          }
  </code></pre>
  
  <blockquote>
    <p>Endpoints</p>
  </blockquote>
  
  <pre><code>http://localhost:8000/api/tasks?owner_id=1&amp;doer_id=1
  </code></pre>
  
  <p><em>(Gives only those tasks where <code>owner</code> and <code>doer</code> are the same employee)</em></p>
  
  <pre><code>http://localhost:8000/api/tasks?owner_id=1
  </code></pre>
  
  <p><em>(Gives only those tasks where <code>owner</code> is specific employee and <code>doer</code> is anyone)</em></p>
  
  <pre><code>http://localhost:8000/api/tasks?doer_id=1
  </code></pre>
  
  <p><em>(Gives only those tasks where <code>doer</code> is specific employee and <code>owner</code> is anyone)</em></p>
  
  <blockquote>
    <p>What I want</p>
  </blockquote>
  
  <p>I want an endpoint like:</p>
  
  <pre><code>http://localhost:8000/api/tasks?both_id=1
  </code></pre>
  
  <p><em>(Which would give me all results from above 3 endpoints)</em></p>
  
  <p>I want <code>django-filter</code> to do filtering exactly like:</p>
  
  <pre><code>Task.objects.filter(
      Q(employee_owner__id=1) | Q(employee_doer__id=1)
  )
  </code></pre>
  
  <p>How can I achieve that ? Thank you.</p>