partner-contact/partner_contact_access_link/models/res_partner.py

# Copyright 2020 Tecnativa - Jairo Llopis
# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).

from odoo import models


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

    def open_child_form(self):
        """Open child contact form from the parent partner form view"""
        return {
            "type": "ir.actions.act_window",
            "res_model": "res.partner",
            "res_id": self.id,
            "view_mode": "form",
            "view_type": "form",
            "target": "current",
        }