So for “tbb” you need to be on a browser and you may select some text, which will in turn become the $Text of the note.
For “tbc” (choosing a color) and “tbd” (Due sprints), you need to select one or more notes.
For “tbs” you should be on the screen, that you want to capture.
The “Due sprints” in more detail: http://forum.eastgate.com/t/script-timed-due-app-sprints-for-selected-notes/2266, just translated to Alfred…