Limit choices via Constraint

Hello,

We have a parent & child models that refer to a third model via M2M. I’d like to restraint the options of the child to the references in the parent. limit_choices_to would not work

Is there a way to do the same using CheckConstraint ?

In what way and to what level do you want to do that?

Because in view that could be achievable Through forms, but you need to provide more information in order to help you.