As a user I would like QueryableDataProvider to avoid blocking the UI while executing the query on the database server.

When a filter dialog is shown (Report Filter or Label Filter) for OLAP Hierarchy, it contains the items only for the selected level. Instead items from all levels could be visible, so you won't have to open additional dialogs to filter them (show them like a tree).

As a user I want to hide the Grand Totals for specific groups.

If a group has only one item in it, I only want to show the total row and not being able to expand it.