title: Import-Export with "multilevel" models
body: <p>I am figuring how can I manage this situation with django-import-export using the same excel and differents models with differents djangoapps. I have the following models:</p>
  <pre class="lang-python prettyprint-override"><code># employees/models.py
  class Employee(models.Model):
      name = models.CharField(max_length=100)
      job = models.ForeignKey(Job, on_delete=models.SET_NULL, null=True, blank=True) 
  </code></pre>
  <pre class="lang-python prettyprint-override"><code># jobs/models.py
  class Job(models.Model):
      value = models.CharField(max_length=100)
      department = models.ForeignKey(Department,  on_delete=models.SET_NULL, null=True, blank=True)
      place = models.ForeignKey(Place, on_delete=models.SET_NULL, null=True, blank=True)
  
  class Department(models.Model):
      value = models.CharField(max_length=100)
      business = models.ForeignKey(Business, on_delete=models.SET_NULL, null=True, blank=True)
  
  class Place(models.Model):
      value = models.CharField(max_length=100)
      business = models.ForeignKey(Business, on_delete=models.SET_NULL, null=True, blank=True)
  
  class Business(models.Model):
      name = models.CharField(max_length=100)  
  </code></pre>
  <p>On excel I have following values:</p>
  <pre><code>xls_employee_name, xls_employee_job, xls_business_name
  Jon Doe, Web Developer, Company 1
  </code></pre>
  <p>I know how to import employee name and his job because Job is directly related by ForeignKey. But how can I import business name?</p>
  <p>Below is the code for employee name and his job:</p>
  <pre class="lang-python prettyprint-override"><code># employees/resource.py
  class EmpleadoResource(resources.ModelResource):
      name = fields.Field(attribute='nombre', column_name='Nombre')    
   
          job = fields.Field(
              column_name='xls_employee_job',
              attribute='job',
              widget=ForeignKeyWidget(
                  Job,
                  field='value'
              ))
  
      class Meta:
          model = Employee
          fields = ('name','job',)
          skip_unchanged = True
          
          
  
      def before_import_row(self, row, **kwargs):
          self.job = row[&quot;xls_employee_job&quot;]
  
      def after_import_instance(self, instance, new, row_number=None, **kwargs):
          Job.objects.get_or_create(name=self.job)
  </code></pre>
  <p>Is it possible to import business name using one excel? I appreciate if someone could guide me. I'm also pretty new with django.</p>