These little buttons just enlarge or shrink the size of the staves. Here we went to the Track window and selected three tracks. Then got over to the Score window at about measure 51. All three staves would show up here, if the staves are greatly reduced in size. The problem, as you can see, is that if you shrink too much, you can have difficulty making out the notes; plus this sequencer tends to get a little confused when the staves start getting too little, as you can see on the bottom slide (though to be fair, there are some quick-display, shortcut options provided, and one or two of those are being used here). The up/down arrows/spinners reduce/enlarge the note/staff size and the left/right spinners reduce/enlarge the width of each measure. We shrunk notes by 3, then by 5, then narrowed the staves by 2. [And this is only for display purposes. At 1024x768, the Score window can be much larger, obviously (the graphic, here, just would have been too large).]