Description
When you click 'Build XML Site Map' in Settings > System > Global Settings, select a multisite in the drop down list and specify corresponding folder in "Site Map Folder" textbox the generated file doesn't reflect multisite settings.
 
Solution
http://www.viart.com/downloads/admin_site_map_xml_build-4.1.zip
 
Extract 'admin_site_map_xml_build.php' into 'admin' folder of your shop replacing existing file. Please do not forget to make a backup copy of the current file in case something goes wrong.
 
Also before generating a new XML Site Map please delete the previous files.