Configure Current Navigation in SharePoint 2010
Configuring current navigation settings for each SharePoint 2010 site is similar to global navigation. You have the same options to automatically show pages and subsites. You have these options to determine what items appear in the site’s current navigation:
Display the Same Navigation Items as the Parent Site: This option displays the current navigation items using the settings of the parent site.
Display the Current Site, the Navigation Items below the Current Site, and the Current Site's Siblings: This is the show-everything option. This option shows navigation items from the current site, parent site, sibling sites, and any children sites.
Display Only the Navigation Items below the Current Site: This option doesn’t show any sibling or parent navigation items or items from the current site; only items from child sites display.
Choosing the Show Pages and Show Subsites options makes navigation items show for pages and subsites in the current navigation of parent sites, sibling sites, and child sites any time those sites opt to show the navigation to the site you’re configuring.