It's currently not possible to show a goal's roll-up goal (i.e. grandparent goal) on a grandchild epic or feature record)
The roll-up goal can often provide helpful strategic context and ensure that the correct parent goal is selected on an epic or feature
Users select the incorrect parent goal on an epic or feature
Users have to open the parent goal in order to see the grandparent goal, taking them away from the direct context they were previously on or viewing (i.e. epic or feature)
Allow the grandparent roll-up goal to appear as a read-only field on a grandchild epic or feature
Include the grandparent roll-up goal as an action in automation rule on grandchild records or in "same as" automation actions to support custom goal fields