B2B INDUSTRY NO FURTHER A MYSTERY

I've 2 O365 tenants and want to simply grant end users from the company tenant over to the partner tenant for SharePoint On the internet. The B2B sounds like It could be the easiest, but will it guidance Sharepoint On-line. The only real example I see in MS docs is for any Groups Channel.You could find other businesses that make use of the B2B eCom