Odoo is a multi-company ERP system, so without any problem, each of them can be managed completely independently. The chart of accounts, fiscal positions, taxes, journals, and the location of the country in question is not shared between companies. All of this is independent so you can manage each company with their own accounting, products, and so on.

You have to activate the multi-company function and establish or indicate for each product, customer, or supplier their owner. With this indication, only each company is going to view their own information. The security of the user is important because you need to indicate which company can acces