i have read the text tutorial many times but can not really get it.
so i think video tutorial can help more
Effectively, you are allowing one set of users to access course that are assigned to one company node, and other users to access the other course for the other company node.
Some users will exist in Company 1, and others will exist in Company 2. If you want to define different layouts / templates for each company that they see when a student navigates to their portal, then you'll need to do this from the Control Panel / URL section of your hosting provider (or have them do it for you). Something like:
they'll both redirect to the same location, the folder that contains your installation of Forma. On arrival, the Forma system will work out how they got their and offer up the respective template based on the URL, the setting for this are within System Admin setting.
After this, create 2 courses; Company1Course & Company2Course.
Now you can assign each user to their respective company and each course to the respective company. Each user that you log in as should only be able to see the course within their company
Company1User -> Company1Course
Company2User -> Company2Course