Doesn’t work (Windows)
I get 0 result, as (if) nothing is actually selected in the binder itself. → (I have opened another document from the binder since creating the collection. – Document which doesn’t contain the searched word, obviously.)
. . . . . . . . . . . . . . .
OK. One needs to first select all of the collection’s documents, then right click + “reveal in binder”.
Then “search binder selection only”, in the search options, like @kewms said.
(So, as it turns out in the end, the collection’s only purpose is to serve as a “memory” for the two combined searches.)
In other words, as it is now (bug ? maybe) we are not actually searching the collection. But rather the binder’s selection. (Which we now have set here to match the collection.)
That, so far, is the only way I could get it to work…