I'm looking to do the same!!!
Right, I've resolved my issue basically what i was doing before was dragging Status.Title into the criteria window, what I should've done was to drag the actual relationship Status, and that was basically it did the same for any other drop downs i needed like Latest Assignment Group.
Hope that helps.
What happens when you run the query, does it go straight to a list of results or something else?
Having a look at a similar query here I have something like:
Current Assignment.Group Is Equal to Prompt User
AND Status Is Equal To Prompt User
When I save and run the query i get a dialog box which prompts me to select what Status I want and what Group I want and then the results appear according to the criteria i've selected.
I saw just after posting you've already sorted it, sounds like it's working fine now then.
The same problem had me a little puzzled when I first came across it, the same as when you're specifying criteria.
If you drag the attribute from the top level onto your criteria window you may only have a few conditions to select from, such as 'is equal to', 'is current group' etc.
Instead if you drag the attribute onto the criteria window from a more drilled down level such as 'status.title' you get more conditions to play with.
Hmm so from what you're saying even if you drag the attribute status.title which is at a lower level in the criteria pane it should still work so by that i mean it will prompt you and ultimately give you more options against the criteria. However, dragging status.title into the criteria pane and then selecting the criteria you want and saving and then running the query should work from what you say, but i couldn't get it to work.
I guess what you're referring to, is it gives you more conditions regardless of if you want a prompt or not, interesting i'll bare that in mind for future queries i create, thanks :-)