I am sure this is a newbie question (as I am)
as were we all. Anyway …
… what you need to know here is that a reference to a related field by default returns data from the first related record, via the (explicit or implicit) sort order for the relationship between your current context and the reference target – Reminders … Staff, in this case.
If you want a list of the addresses, you need to tell FM so, e.g. by using
List ( Staff::StaffWorkEmail )
or, for use in an address field, probably
Substitute ( Staff::StaffWorkEmail ; ¶ ; ", " ).
And you can uncheck “Collect across found set”, because your found set in that moment is in reminders, which don't have addresses.
Another way would be to first GtRR, i.e. use the step
Go to Related Record [ Staff ; matching current record only ]
travelling the relationship chain as outlined above; now you could use “Collect across found set”, because the found set is the list of recipients.
Be aware, though, that if this cardinality is true (where many >-- one) …
Reminders >-- Programs --< ProgramStaff >-- Staff
… you would lose the context of the reminder you started out on, because none of the found Staff records can be uniquely associated with any reminder; OTOH, you could capture the relevant reminder data in $vars (title, date, body etc.) before you change the context with GtRR, and pass those to the options of the Send Mail step.
Hope this is clear as mud …
I used the List() function and both addresses auto-magically appeared. Thank you for your help!!