4. Expanded View (B-Type Chart)
Upper and lower levels can be displayed as a whole in the B-Type Chart view.
To display the B-Type Chart view, tap the chart icon at the upper right.
Tap the center frame, and you will return to the upper level. Tap any of the surrounding frames to navigate to the lower level.

To zoom for a magnified view, touch the screen with two fingers and move them apart.