You can view up to 4 different tracks at one time in each of the calendar views (Month, Week, Day). You can select the tracks you want to see via the menu on the left side of the screen. Track options will depend on the specific menu item selected, and available menu options will depend on a user's specific roles/permissions. See the "Selecting A Track" section in How Do I Navigate The New Plan Page? for more details.
Once 4 tracks are selected from the side menu, the other options will become disabled until one of the current tracks are deselected.
Month View
Tracks are stacked on top of each other in Month view. So, while you can view up to 4 different tracks at a time, if multiple events exist on each track, you might have to scroll within a given day to view everything.
Scroll within a specific day to view all of the programmed events for that day.
*Note: if you want to view more details about a specific programmed track event, hover over the event to view a full description.
Week View
In Week view, tracks are displayed side-by-side.
If a track is missing workouts, the column will remain empty. 
*Note: you can collapse and expand track events in Week view. Tracks will be collapsed by default. In order to view the full event description tap on the event title bar to expand.
Day View
Like Week view, tracks are displayed side-by-side in Day view. 
Also like Week view, if a track is missing workouts, the column will remain empty.
*Note: Unlike Week view, track events are expanded by default while in Day view.