see how to return dynamic domains from python side: https://www.youtube.com/watch?v=dq5Vtj_pwuI&t=197s

Hi,

Please try the below:

from odoo import fields, models,api

class HrEmployee(models.Model):
    _inherit = 'hr.employee'

    model1_id = fields.Many2one('model1')
    model2_id = fields.Many2one('model2')

    @api.onchange('model1_id')
    def onchange_model1_id(self):
        for rec in self:
            return {'domain': {'model2_id': [('model1_id', '=', rec.model1_id.id)]}}

Regards