@api.onchange('project_test_ids')

 

 

 def onchange_projecttest_ids(self):  

       domain = {}

       if self.project_test_ids:

           domain = {'test_id': '''[('id', 'in', %s)]'''%str(self.project_test_ids.ids)}

       else:

           test_ids = self.env['project.tests'].search([])

          domain = {'test_id': '''[('id', 'in', %s)]'''%str(test_ids.ids)}

  return {'domain': domain}