class Model1(models.Model):
...
class Model2(models.Model):
m2m_field = models.ManyToManyField(Model1)
m1 = Model1.object.get(...) #он просто у меня есть
m2 = Model2.objects.all()
x = m2.filter(m2m_field__contains=m1)
class Model2(models.Model):
m2m_field = models.ManyToManyField(to=Model1, related_name='second_models')
m1 = Model1.object.get(...) #он просто у меня есть
second_model_queryset = m1.second_models.all()