I create a query with filter "Content with type User" and add the following layout:
Display mode: content
Display type: Summary (also tried it with Detail)
Properties: Added a custom field and selected "Exclude from display"
Grouping property: Selected the field above
Order: Unordered list (also tried with ordered list)
When I use this query, my users get grouped the way I want them too, that works fine.
But now I also want to order my users, first by the group and then by the name. But as soon as I add a Sort Criterion with a Profile Part Content Field (I use the Profile Module), my query breaks and I get 0 results.
See my thread (http://orchard.codeplex.com/discussions/394501
), they told me to file a bug.