Sorry about that Mark, I didn't read your question carefully enough.
The Element ID manager allows you to sort an element type by the various attributes assigned to it. You can create many sets of criteria for sorting.
It is documented well in the on-line help for 8.1 at
http://download.graphisoft.com/ftp/publishing/ac_help/wwhelp/wwhimpl/java/html/wwhelp.
htm
I was trying to do an example for you of sorting countertops made with slabs by layer, fills (which denote different materials) and also thickness. Unfortunately AC crashed when saving the settings.
Best if someone else answered this.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"