I'm not shifting anything. How can one have agency if they don't know that there is an opportunity? i.e. If an opportunity is open to all; but is only presen

I'm not shifting anything. How can one have agency if they don't know that there is an opportunity? i.e. If an opportunity is open to all; but is only presented to one class then you are in general only going to get applicants from the class that you presented the opportunity too.