You would need to open the MIDI object in question in the MIDI Editor, e.g. by double-clicking it in the Music Maker arranger. The MIDI Editor features its own menu bar at the top fo the screen, where you would find an "Export MIDI" option in the "File" menu. This way, you can dump a Music Maker MIDI object into a standard MID file. Unfortunately, there's no feature that would allow you to combine multiple MIDI tracks from one Music Maker project into one single multi-channel MID file.
Music Maker's MIDI Editor doesn't feature any traditional notation/score view (as you would e.g. find in the Samplitude product lines). It's limited to the piano roll/matrix view, and a special "Drum Editor" view that is better suited for non-melodic/drum software instruments. If I do understand correctly what you're after, it sounds like there might be some VST plug-in out there that could do that job (i.e. real-time visualisation of MIDI date), but I couldn't recommend one off the top of my head.