Answer:
Oracle doc...
7.3.4 Copying a Database Application Page
You can copy a page from the current application or from another application. During the copy process, you can also copy shared components or change mappings to shared components in the target application.
To copy a page:
Navigate to the application you want to copy to:
Navigate to the Workspace home page.
Click the Application Builder icon.
Select an application.
Select a page.
The Page Definition appears.
In Tree view:
Under Page Rendering, select the page name.
Right-click and select copy.
In Component view:
Under Page, click the Copy icon.
For Copy Page Option, select one of the following:
Page in this application
Page in another application
Follow the on-screen instructions.