What happened to the show only topic functionality?

In moodle 2.2 and probably earlier, there is a nice little icon in the upper right corner of a section that allows you to focus ONLY ON THAT SECTION when developing the course.  This is a very handy feature if you are developing topics with a lot of content. 

This is the icon on the moodle 1.9.x - 2.2.x instance




 One of our course content creators called me today saying "where is that little edit box ?".  They are working on a different server with moodle 2.3.  Sure enough, the icon is gone.

 Refactored in moodle 2.3 as a course setting.

  This is the forum that discusses the refactoring.  This is the moodle doc page explaining the refactoring.

The functionality has been moved into course settings under course layout

After choosing Show one section per page and saving the result and clicking on a section title, you can see the other sections around it collapsing with navigation links in place of the content.

Finally, there is also a block that appears that allows you to browse dynamically, rather than sequentially, very nice.

 

 

 

Moral of the story?

Ask the right question, get a good moodle forum and doc page to answer the question.
My question was "moodle show only topic moodle 2.3".