Thanks guys. I'm doing that already. I thought I'd seen folders in the Mixer window in a screenshot, but maybe that was some other program. With the Visibility feature, it works just about the same (just a couple extra steps for me to open then close the visibility pane as I usually keep it closed).
MacPro 2x 2.93 Hexacore | 32 GB RAM | 500GB SSD | OSX 10.10 | Focusrite Liquid Saffire 56 | Nuendo/Cubase (latest) | UAD-2 Satellite Quad Core | Fractal Audio Axe-FX II | Agile Septor Elite 928 EB Tribal Purple 9-String Guitar