This is about having separate sections (with green titles) of actions and about being able close sections manually and by configuration.

http://wiki.magnolia-cms.com/display/UX/Action+bar

The overall design idea is that the most common actions (and only those) are placed in the always visible, non-closable first section of the action bar, and that all other actions are organized in further sections are closed by default. Note that sections should, if possible, remember the "open/close" state.

Please also note that this is not about having sections and/or groups auto-close on devices with small screens.