You can search for a target from the Home tab (which is also called the Grid Control Home page) or from any of the subtabs on the Targets tab.
When you search from the Home tab, use the Search drop-down menu to
select a target type and then enter a target name (or partial name) in the adjacent
field. For example, if you enter the letters "sys", Enterprise
Manager locates every target with a name that contains those characters and
then displays them on the All Targets page.
When you search from the Targets tab, Enterprise Manager limits the search to the current subtab. For example, if you are on the Databases page, Enterprise Manager searches for database targets only. To search for any target type, display the All Targets page before you search.
Note: Enterprise Manager does not support the use of wildcards, such as asterisks (*), when you are searching for a target name.
Viewing Your Oracle Environment at a Glance
Viewing a List of Managed Targets
Enterprise Manager Information Roadmap