I have 2 classes "class" and "student" where the relation between them is one2many. i.e one class will have many students

Then the third class to map where i need to make an entry by selecting one class and selecting one student. So i would like to filter students only that of the class selected.

I implemented the below domain filter

<field name="class"/> # many2one field
<field name="student" domain="[('student.cols.id','=',class)]"/>  # many2one field where cols is the many2one field to class "class". In the right side i am able to get the id correct

It fails with the below error message

raise ValueError("Invalid field %r in leaf %r" % (left, str(leaf)))

Kindly clarify. Thanks for your time