Updated answer (Nov 15, 2019)
- From version 3.3: (Various pages of Preferences window has been modified for visual enhancement)
Preferences -> Keys -> Navigation Shortcuts -> Shortcut to choose a split pane -> Select "⌘ Number" option and select No shortcut for other options.
- Prior to version 3.3:
Preferences -> Keys -> Navigation Shortcuts -> To switch split panes -> Select "⌘ Number" option.
Old Answer Go to iTerm2 -> Preferences -> Keys -> Navigation Shortcuts -> To switch split panes -> Select "⌘ Number" option.
The switching works like the same as browser tabs. i.e., You can switch from 1 to 8 using the numbers and ⌘+9 to the last/ninth tab. Also make sure that no other shortcuts are bound to the same key combination (such as for switching tabs), which may override the preference setting.