question

As explained by @Matthew Gillespie in this answer, companions can be created and directed by activity triggers in a patient track. Also you can see @cliff.king's forum post here.

These are the steps for probably the simplest way to do this:

1. Create a separate patient track with the activities that you want the companions to go through. This is important because if you use the same patient track, companions will be created for the companions of the patient and so on.
2. Make a new PCI for the companions and reference their separate patient track.
3. In an "Activity Started Trigger" (such as when your patients enter the model), select the "Create Companions" option in "Add new trigger instruction." Then the only fields you should need to edit are the "Number of Companions to create" and the "Companion track" (the value can be completely replaced by the name of the patient track you want the companions to go through, surrounded by quotation marks.)
4. In the same trigger you can "Start an activity for companions." It will reference the Activity ID that you enter for the patient track in which the companions were created.
5. You can use as many triggers as you wish to start separate activities on the companions. For example, when the patient exits the model you can add an "Activity Started Trigger" to start an activity on the companions to travel to the exit area. (As a side note, make sure that the patient locations for the companions are connected in the Flowchart, such as the Waiting Room to the Patient Exit.)

I've attached a small example model so you can see how this works. Let us know if you have any more questions or if this is unclear.