At the first, you have to select the number of players involved manually and save them as a filter, e.g. screens at all classrooms or at all retail's POS.
At about 29 sec., there is a pop up windows, click "YES". Basically what it does is it save the players that you have selected (i.e. before 29 sec. mark) and save them as a Filter Name.
You can call it up in future when you want to do deployment at the same video's top left screen where there is a "Search" function.
See the video at the URL below.