Asset explorer-Overview tree, with which you can navigate between different depreciation areas

In Asset explorer,Overview tree, with which you can navigate between different depreciation areas,in ECC 6.0EHP 7,could see folders created for each GAAP reporting.Can you please let me know how these groups are created.Please check the screen shot attached.Can you please advice which tcode ius used to created the folders for different dep areas and can we hide any dep area if we donot need it to be displayed.