Facebook friends blocking is great feature that allows you to get protected from problematic persons that who may make issue for some thing. So u may use that blocking feature.
Here is the tutorial to unlock Facebook friends that you might be missing.
Unblock Facebook friends
Go to lock shaped icon that is left to settings and right to home.
By clicking on that you will see an option called “see more settings”.
Then you can see “blocking” in left side.
Then you will find blocked friend by you
That’s it unblock Facebook friends and enjoy.
This is the complete guide to unblock Facebook friends easily
Here is the video grab the info