I have a table for BoardPositions in my application.
Our organization has 2 co-presidents. Positions are overseen by one co-president or the other (or none).
My table and form have an “OverseenBy” field. I made the field an integer, and on the form I created values of 0:None, 1:Co-President 1, 2:Co-President 2.
This works perfectly so far.
I have decided that it should be more dynamic, incase we add more co-presidents later. So since I have a boolean field in the table called IsPresident, I thought I could populate the drop-down with the actual positions needed. I created a query called “GetPresidents” which contains the following:
Select BoardPositionsKey, PositionName from BoardPositions where IsPresident=true
I changed the table field and form fields to GUID instead of integer, and for Page List Source I put “GetPresidents”. I thought this would give me a drop-down list showing the current Co-President records. This does not work. The drop-down says “No options”. However, when I run the query from the code window, it properly shows the 2 records who have IsPresident=true.
The documentation that you found was Version 2.1, we have Version 2.6 documentation out now, it is continually being updated with more information every day and you will find it more up to date. The lookup display types are currently in progress of being documented.
I have provided a couple of links for you that maybe of help for now.
Can you please take a look at these two links and see if they will help your scenario for a _LookupQuery.
The essence of it is you use a _LookupQuery display type, choose the query and the query at a minimum has to return the primary key and a visible value which is what you will see in the lookup.
I have setup what you are trying to perform (as close as what I think from your images) and it is working for me. Is it possible for you to email me your FDF so I can get a better look? You don’t have to attach to the forum, I can send you an email privately so you can send via that.