In order to target actual Motivated Sellers on Facebook, you have to understand how to correctly build an audience. This will be very important as you begin to create your ads because it determines who actually sees your ads. There are two primary types of audiences you can create on Facebook, a custom audience, and a look-a-like audience.
A custom audience is created on Facebook using data that is private to your page. This includes customer lists that you can upload, engagement on your website, Facebook page and Lead Forms, as well as how long people watch your ads and engage with them. These are the audiences that you will want to use for your retargeting campaigns.
The audience for Real Estate Related Industries is called a Special Look-a-like Audience. These are audiences that have been created based on a Custom Audience you are tracking. They are meant to find other potential clients that match a 1% similarity to the people in your Custom Audience pool.
To start creating your audiences you can follow the steps outlined here.