from odoo import fields, models class PosComboLine(models.Model): _name = "pos.combo.line" _description = "Product Combo Items" product_id = fields.Many2one("product.product", string="Product", required=True) combo_price = fields.Float("Price Extra", default=0.0) lst_price = fields.Float("Original Price", related="product_id.lst_price") combo_id = fields.Many2one("pos.combo")