# res_company.py 
class Company(models.Model)
        _inherit = 'res.company'
        supplier_id = fields.Many2many('res.company', string='Vendor')
 

When creating a product, it is visible to all companies. By default, a single product.template (id, ) entry is created  and related product.product(id, ).
​How to set a supplier depending on the company at the time of the product creation?

Product 1 company A -> supplier1, supplier2 
Product 1 company B -> supplier3, supplier4