You need to use Look-a-like. It is about what you need.
Literally English Look-a-like (look-alike, localic) is a "search for similar". This search, the system selects a specific target audience and show ads only to her. This targeting method selects users that the behavior is similar to those who have already visited your site and performed the target action, for example, issued an order in the online store.
Look-alike is the learning target: on the basis of performed target actions on the website it analyzes user behavior and generates certain behaviors. Next, it searches the network users that the behavior is similar to the model, and displays ads to them.
In General you need more help with Facebook, everything is written and narrated.