Focus on the layers you want : http://aescripts.com/category/scripts/alan-eddie/
Click = Isolate in timeline, shy and lock other layers.
Shift Click= Isolate layers based on label colour (CS5+).
Alt Click = Isolate in timeline with solo, shy and lock other layers.
Alt & Shift = Solo selected layers in timeline.
Isolates layers in your comp based on what modifier keys are held down. Adds a bug to the comp to indicate being in "Isolate" mode. Simply click again to un-isolate. Script comes with a user interface or there is a version for use in other toolbars. Instructions in video to set up a keyboard shortcut to use the script too. See video on AEScripts.com or alaneddie.com for more information and tips.