How to not toggle the Project sidebar off, when switching between editor tabs and sidebar

Hi,

How to switch between the Project Structure Tab and Editor Tabs without making the Project Structure Tab disappear after hitting the shortcut again to focus on Editor Tabs?

The shortcut I am using is under Tool Windows -> Project (currently set to ⌘ + 1, on Mac OSX)

I did not find anything about it, in the documentation.

Thanks!