This feature is available in Enterprise and Ultimate editions.
Click Portfolio > Planning > Portfolio Tree.
Select the parent portfolio item for which you want to create a child portfolio item, and then click Add Child Portfolio Item.
The Portfolio Item dialog box opens, populated with the parent portfolio item information.
Change the Title and Risk field values to reflect the new child portfolio item details. You can also add other descriptive information to fully define the child portfolio item (For example: Description, Swag, Value Scale, Status, Owner, Priority).
Click Save. The system inserts your new child portfolio item under the parent in the list.