partner-contact/partner_contact_department/models/res_partner.py

# © 2014-2015 Tecnativa S.L. - Jairo Llopis
# © 2016 Tecnativa S.L. - Vicent Cubells
# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl.html).

from odoo import fields, models


class ResPartner(models.Model):
    _inherit = "res.partner"

    department_id = fields.Many2one("res.partner.department", "Department")


class ResPartnerDepartment(models.Model):
    _name = "res.partner.department"
    _order = "parent_path"
    _parent_order = "name"
    _parent_store = True
    _description = "Department"

    name = fields.Char(required=True, translate=True)
    parent_id = fields.Many2one(
        "res.partner.department", "Parent department", ondelete="restrict"
    )
    child_ids = fields.One2many(
        "res.partner.department", "parent_id", "Child departments"
    )
    parent_path = fields.Char(index=True)