Can I Password Protect Different Directories with Different Logins?

I’ve got a WP site that I want to use to display different content for different customers, after they’ve logged in. (If they haven’t logged in, then I only want to display standard menu options (like About Us, Contact Us, etc.)

The pages for each customer would use the same template and be titled the same, only the content would be different.

Is there a way to display different content for each customer after they’ve logged in?

The only approach I can think of is to create separate sub-directories for each customer and then create a unique username and password per each customer sub-directory. This may not be the best approach because I could end up with hundreds of customers.

Is there a better way to do this? Thx