- do a search
- make sure the results include a folder with sub-items
- select the search as a collection
- select the saved search
- select the folder in the collection
It will always be displayed in the editor window in document mode, never as a corkboard or outline. You can change the view in the normal way, but this setting does not stick: if you view another item and then go back to the folder, it is displayed again as a document.
