1👍
✅
This should work:
Newsletter.objects.filter(
id__in=[subscription.newsletter.id for subscription in
Subscription.objects.filter(subscriber=user)]
More readable(and verbose) version:
subscriptions = Subscription.objects.filter(subscriber=user) # all subscriptions for a given user
newsletter_ids = [subscription.newsletter.id for subscription in subscriptions]
Newsletter.objects.filter(id__in=newsletter_ids) # answer
Source:stackexchange.com