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First method
    @api.onchange('sale_order')
    def _onchange_product_id_domain(self):
        product_ids_list = []
        for invoice_number in self.sale_order.order_line:
            product_ids_list.append(invoice_number.product_id.id)
        # for empty field if sale_order field will empty
        self.fieldNameWhereproductsdropdown(product.product) = False
        return {'domain': {'fieldNameWhereproductsdropdown(product.product)': [('id', 'in', product_ids_list)]}}
        
        
        
Second Method (List Comprehension)
 @api.onchange('sale_order')
    def _onchange_product_id_domain(self):
        self.description = False
        product_list = [invoice_number.product_id.id for invoice_number in self.sale_order.order_line]
        return {'domain': {'description': [('id', 'in', product_list)]}}