In the past, my Facebook wall showed me when a friend had made a new FB friend, and also told me who that friend was. Now, my wall does not show when any of my friends make a new friend. This only shows up on my ticker, which I never check.
You can add them to the list Close friends. Every action of them will be shown, including adding new friends or following someone. No one know your Close friends list, neither those in this list.
But you will be able to see such notifications only if your friends allows to share it with their friends.