Memory is getting hazy but I recall that this was an option in Version 5. It isn't, and I don't think it needs to be, in Version 6.
If you erase the folder (by whatever means), all its contents are erased automatically. If you want to erase the contents of a folder, but not the folder itself, the best way is to create a task, specify a folder erase and, in the Add Data dialog, untick the option to erase the folder. If you want to erase only some of the contents of a folder, you can create a task with multiple entries, or (preferably in my view) you can use either context menu erasing or drag and drop on to the Eraser Schedule window to delete the items singly or in a group or groups.
I think that covers all the bases except the situation where the items to be deleted have different permission levels. Then, Windows being what it is, it is probably best to run Eraser elevated and use context menu erasing; drag and drop will not work if the source folder and the Eraser window have different permission levels.