I want to display the following: 
op.student Table has relation to Course : one to many 

course_detail_ids = fields.One2many('op.student.course', 'student_id', 'Course Details', track_visibility='onchange')

Now op.student.course has many2one relation with op.batch 

student_id = fields.Many2one('op.student', 'Student', ondelete="cascade")

course_id = fields.Many2one('op.course', 'Course', required=True)

batch_id = fields.Many2one('op.batch', 'Batch', required=True)

I want to display the batches in the tree view. I'm able to display course_detail_ids but can't figure out the issue with batch_id with any suitable widget like manytomany_tags etc. Please let me know.
What to do ?