Global Search is currently removed from Moodle 2.2.
As part of GSoC '13 project, I've re-written Tomasz Muras's Global Search implementation for the current 2.6 (dev) master branch.
You may view the demo and play with it here: http://global-search.jmuras.com/
( Username:search_admin Password: Search_admin1 )
The docs are here: http://docs.moodle.org/dev/Global_search
Issues in Epic
|MDL-46309||Fix global search unit tests||Open||Unassigned|
|MDL-46310||Move from modules support to subsystems and all plugin types support||Open||Unassigned|
|MDL-46311||Define common search APIs||Open||Unassigned|
|MDL-46312||Create a renderer for global search||Open||Unassigned|
|MDL-46314||Improve global search performance||Open||Unassigned|