In EV11.0, Enterprise Vault Search (EVS) allows end users to perform search across multiple archives from same or different content source. This feature helps user to find items which may exists in multiple archives. There are two ways to perform a search on multiple archives.
1) Through Simple Search Pane: Click on the down arrow available in the simple search text box and then click on Choose Folder.
2) Through Advance Search Pane: From the search property drop down select Folder option.
A new window will be launched with a list of archives. Place a check mark against the archives or folders on which you want to perform a search. In the breadcrumb you will see "Multiple archives or folders are selected".
When you perform a search across multiple archives from the same content source (For eg: search on multiple Exchange archives) then the columns and actions on items (Export & Restore) do not change.
However generic columns and limited actions on items will be available if you perform a search on multiple archives belonging to different content source. (For eg: Search on Exchange and FSA archives)