Use the Navigator in Song View to see an overview of your entire project, and quickly focus on specific areas intuitively.

Click and drag horizontally on the Navigator frame to scroll and change the current area viewable in the Song View timeline:

Click and drag on the left & right handles of the Navigator frame to expand the area viewable in the Song View timeline:

Double-click on the Navigator frame to reset it's size, and view the entire project in the Song View timeline:

Click and drag vertically on the Navigator frame to zoom in & out of area viewable in the Song View timeline or alternatively, use a two finger 'pinch to zoom' gesture on your trackpad: