How to Add Complex Domain Filter on Many2many Fields in Odoo

add_domain_many2many_field_odoo.py

@api.multi
def _add_domain(self):
    user_obj = self.env['res.users'].search([('department_id','=',self.env.user.department_id.id)])   
    if user_obj:
        domain = [('id', 'in', user_obj.ids)]
    else:
        domain = [('id', '=', -1)]
    return domain

your_many2many_field = fields.Many2many('model.name','your_many2many_table_name', 'column_1','columns_2', string="My many2many Field",domain=_add_domain)       

How to Add Complex Domain Filter on Many2many Fields in Odoo