How to filter one model by another if it doesnt have relation

I have 2 models and model ObjectList has m2m field to CounterParty but i need to show info from CounterParty model filtered by object

How am i suppose to do it?

class CounterParty(models.Model):
    name = models.CharField(max_length=150, verbose_name='Наименование')


class ObjectList(models.Model):

    name = models.CharField(max_length=250, verbose_name='Наименование')

    contractor_guid = models.ManyToManyField(CounterParty, related_name='object_contractor',default=None, blank=True)

I know this is not right but it should look like this

object = ObjectList.objects.get(id=1)
a = CounterParty.objects.filter(object_contractor=object)

>Solution :

Your attempt is correct: you use the related_name to query in reverse. The fact that it is not defined on the model is not relevant: queries can be done in all directions. If you however don’t need the ObjectList, you can just use:

CounterParty.objects.filter(object_contractor__id=1)