Ability to select multiple notebooks regardless of notebooks grouping

[The big Discovery 10]

While the notebook groups are useful, I find myself often wanting to see notes from only a few notebooks in a large collection of a notebook group. While I could create a new group for these two notebooks, I do not always want this function, so I'd then have to move them back to the former group, etc; I don't really think the notebook abstraction as implemented is as powerful as it could be.

Ideally I'd like to be able to ctrl+mouse click on which ever notebooks and show all those notes.

Thanks