layer hidden except when selected?

[p0026376]

Hello all, I remember seeing a block at one point that had some components of it that were hidden until you selected the block.

 

so for a basic example, normally you would just see this:

 

SHAPE

 

but when you select the block you would see:

 

_______

|SHAPE|

--------

 

Anyone know how this was done? I believe I was using AutoCAD MEP 2009 at the time.

 

thanks!