sorry for inconvenience, category_type is Many2one type field as you can see in mytests Model.

category_type = fields.Many2one('donation.types', string='Category Type', compute='_compute_category_type', store=True)

@api.depends('donation_category')
def _compute_category_type(self):
for test in self:
if test.donation_category:
test.category_type = test.donation_category.parent_type and test.donation_category.parent_type[0] or False
else:
test.category_type = False

try this

related records from Many2many field to Many2one.

you want to update value from many2many field to many2one?

yes, I want to update from many2many to many2one, this is what i mentioned twice and don't know who was in very hurry to mark your Answer, they should be wait for feedback or a reasonable time period to mark Best Answer. anyway, as mentioned :

I want to update from many2many field to many2one

when user Select a Category in mytests field donation_category the related records from donation.categories field parent_type should be pupulated in mytests field category_type to select one.

hope it cleared now.

regards

what if there is multiple values in many2many field?

hi, @Mehjabin Farsana(Metalinks IT Consulting&Solutions)

yes there are multiple values and this is why we use many2many field.

i have modified as below and it works with multiple values... but please check if there is anything needs to consider and i missed / overlooked.

-----------
donation_category_id = fields.Many2one('donation.categories', string='Donation Category')
category_type_id = fields.Many2one('donation.types', string='Donation Type')

@api.onchange('donation_category_id')
def _onchange_donation_category(self):
if self.donation_category_id:
parent_type_values = self.donation_category_id.parent_type.ids
self.category_type_id = False
return {'domain': {'category_type_id': [('id', 'in', parent_type_values)]}}
else:
self.category_type_id = False
return {'domain': {'category_type_id': []}}
-----------

regards