Here are the steps:
- Use Locksmith to create locks for each of your teams' collections. Make sure each lock is configured to hide menu links from unauthorized visitors.
- On each lock, add a key that requires the customer to be tagged with a tag of your choosing - pick something that corresponds to their team.
- Add links to each of your team collections to your shop's main navigation menu.
- Create a brand new page called "Team Login" (or another title of your choosing; use the page content to refer the customer to your main menu), and add a link to it to your main menu.
- Use Locksmith to create a lock for that page. Make sure the lock is configured to not hide menu links from unauthorized visitors. Then, add one key per team, each key requiring (1) the customer to be signed in, and (2) for them to enter in a passcode you choose for their team. Before saving each key, hit the key's "Advanced Settings" button, and set up autotagging for the customer - use the same tag that's required for the team collection lock.
With this setup, you'll be able to direct customers to the login page you created, where they'll be autotagged according to their team. Then, Locksmith will see that tag, and automatically reveal the appropriate collection link in your main menu.