You can add Facebook comment feed in “Other” blocks tab.
Notice: in order to have a block working correctly, you need to set up integration with Facebook in advance.
There is “Feed ID” item in settings. This item can be used when you need to create several comment feeds for different groups of users, employees or students. You can assign different IDs for every feed. For example, 1 and 2. Messages in both feeds won’t be duplicated.