Searching across linked databases

[wordmuse]

Jumping in where both angels and demons fear to tiptoe...

I don't see even the slightest logic problem related to being able to search across databases. That is, if the search function enables you with something like this:

a - search current database only
b - search all open databases
c - search all URDs in this folder
d - search all URD in this and all subfolders
e - search all URDs wherever they may be accessed
f - search the following databases (and use your mouse to pick multiple databases to search)

Seems to me that if I had all of these options (are there any I'm missing?), then I could do what is available to me now, and much more.

At least that's the way I see it. Am I missing something?