You can add customization types such as "Extend a Dimension" as a step to an existing unapplied branch or a new branch that you create. 
- Sign in to your service.
 
- In Oracle Fusion Data Intelligence
Console, click Semantic Model
                        Extensions under Application
                        Administration. 
 
- On the Semantic Model Extensions page, click User Extensions. 
You see the main and existing customization branches. 
 
- In the User Extensions region, under Customization Branches, click a branch to open the Branch page. 
 
- On the Branch page, click Add Step.
 
- In Add Step, select a customization type such as Extend a Dimension.
You see the wizard sequence to add details for the selected customization type.