Table of Contents- Adding additional layers to organize shapefiles

Discussion created by samantham on May 11, 2012
Latest reply on May 12, 2012 by Hardolph
In the table of contents, is it possible to add additional layer groups to organize your shape files? I am not talking about adding a group or basemap layer. Please see image below for a mock up of what I am looking for.

Thanks for your time and help