we need to change default view on Project/Program Hierarchy from Financial Rollup to Effort Rollup.
Sorry. The application does not provide the ability to configure the sub-pages on the Hierarchy tab. This is a stock tab which is not exposed in Studio for configuration like the Project tab.
You can explore alternatives by using links and a user-defined page layout.
For one PPM client, we have disabled the Hierarchy tab, and developed portlets on the Project Dashboard to show additional data from the 'children'.
The added bonus, it prevents the PM from incorrectly deleting 'children' from the Project from the Hierarchy. The drawback, adding children has to be undertaken from 'Subprojects', or quickly enabling the Hierarchy tab.