Thanks @rebeccas. Your solution may be applicable, but not in this situation. I am using a collection which is probably using the wrong formula and displaying way too much of all Status and All Dates. I also have 3rd screen not used which is filtering fine without collection and direct to SPList (like your example), but becomes another manual management fiasco I don't want to deal with each time there is an event and sessions created. My scenario involves a collection groupby and parent/child gallery.
The collection in my screen is getting too much data (completed and planned) from all sessions not related to the item (e.g. like the dates) selected in the gallery from the Event list. It's getting all dates regardless of Status (not just Planned as required). Secondly, only the Sessions list has a lookup column named 'Event ID Title' back to Events list column 'Title', but not the other way around from 'Events' list to 'Sessions' list.
What I want to do is create a collection when Screen2 is made visible grouping (groupby) of the Status "Planned" and StartDate of any Sessions related to the item selected from Screen1 Gallery item of Events list.
The original post has that detail I believe for review again.
Thanks,
Tom
