Some users in your organization may need to have access to multiple companies within your Microsoft Dynamics 365 Business Central tenant or a different tenant which can all be done through Business Central's Company Hub extension. According to Microsoft, the Business Central Company Hub gives you a list of the companies you work in. You can easily add new companies by just providing a URL and a name for the company. The list of companies contains a few KPIs for the company that is displayed for the user if they have the needed access. You also have a list of assigned user tasks for a given company, so you can keep track of work required for each company.
Business Central's Company Hub wont be available for Production environments until the 2020 Fall Release but in the meantime you can create a SandBox with the latest BC version to try it out.
The first thing you want to do is use the global search and search for and select Company Hub and then select New company.
This is where you'll enter in the information to link the other Business Central environments. Just be sure to select Test the connection after you information is entered because if you do not have the proper permissions for both environments it will not work.
Select yes on this screen.
Hopefully this screen shows for you and you can select Yes.
If the login was successful you should now see your linked Business Central environment.
Now that you have linked your Business Central environments within the Company Hub, if you global search for Company Hub you'll see all of the companies and some key stats about that company. For instance, you'll see all company names, which Business Central environment the company belongs to, User Tasks, Overdue Tasks, Cash Accounts Balance, Overdue Purchase Invoice Amounts, Overdue Sales Invoice Amounts, Check Errors, and the last time this page was refreshed.
All in all, it's a pretty nice extension to make your life easier and save yourself time if you have to work with multiple different companies using Microsoft Dynamics 365 Business Central.