from odoo import models, fields, api, _, Command class Partner(models.Model): _inherit = 'res.partner' root_ancestor = fields.Many2one(comodel_name='res.partner', string='Root Ancestor', compute='_compute_root_ancestor', store=True, recursive=True) @api.depends('parent_id', 'parent_id.root_ancestor') def _compute_root_ancestor(self): for rec in self: rec.root_ancestor = rec.parent_id and rec.parent_id.root_ancestor or rec