Currently, it's very difficult to see who can actually view various aspects of your profile and the items you've posted. The options controlling that are buried, and you have to really dig deep to find the "View As" option. But this "Who can see what?" tab, under a dedicated section for managing friends, allows you to do what it says, which is to let you very quickly filter your list of friends to figure out who can see what information and then potentially change that if you're not comfortable with them seeing certain things.
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