It is late already, perhaps I'm overlooking something. If I select "Database" node, all 2314 files from my database are displayed. But if I select drive node D, only files from 1-st levels of sub-directories (1583) are displayed. D has same 2314 files in all sub-directories, as entire database consists of files on D drive. Is this normal behavior? I'd assume that when selecting drive node D, also all 2314 files would be displayed. See attached screenshot.
The Database Node is special, it always produces a "all files in db" scope.
Check the file window settings, hierarchy mode. This looks like you have configured it to display only one level...
(https://www.photools.com/community/index.php?action=dlattach;topic=7737.0;attach=17573;image)
Yes, that was it, thanks! I was looking in right-click menu of drive node and in preferences.
I suggest you read the File Window help topic to learn about this and other File Window features you may have missed so far.
There is also a video for this in the IMatch Learning Center.
The hierarchy mode has nothing to do with Right-click menus in the Media & Folders tree, it also works for categories and collections.