Atom - Move Focus Between Panes
Solution
Ctrl + K, Ctrl + <Arrow Keys>
or check in Settings > Keybindings > Search for focus-pane

Reference
https://github.com/atom/atom/issues/2670#issuecomment-258660394
Ctrl + K, Ctrl + <Arrow Keys>
or check in Settings > Keybindings > Search for focus-pane

https://github.com/atom/atom/issues/2670#issuecomment-258660394