Use transaction ST12 for very detailed ABAP trace and performanc..
Archives : March-2013
http://scn.sap.com/community/erp/blog/2012/02/13/change-documents-for-s..
http://www.sdn.sap.com/irj/scn/weblogs?blog=/pub..
Refer below link for steps to create custom hierarchy data source and to enhance hierarchy data source to modify the structure http://scn.sap.com/docs..