Hyperion Planning application is used for keeping many financial sensitive data, hence it is very important for users to audit all the changes made in system.
Fortunately, Hyperion Planning has the capability of tracking all (or almost all) the changes made in the application, starting from data change to metadata, form definition and so on.
Read this tutorial from Oracle for assistance: http://www.oracle.com/technetwork/middleware/planning/tutorials/pln-audit-trail-097704.html
However, as you have seen in the tutorial, in order to view it you need to pull these records from Relational database that is inconvenient for users. Not sure if this feature can help user create audit report in Planning or not (will try sometime) follow the link: http://www.orahyplabs./2013/12/run-vb-script-in-workspace.html