How To Assign BIAdministrator Role to a Fusion Applications User??

If you need BIAdministrator or BIAuthor in order to be able to access the Fusion Applications OBIEE Home "Administration" link and/or to create a data model, then this will help you to assign the required roles. At present BIAdministrator or BIAuthor role is not available in OIM. You have to add this through BI Domain enterprise manager.
Following are the details

1. Log on to the BI Domain Enterprise Manager. If you do not have access to this then add the role to you id in OIM  e.g.       http://host:port:10201/em
2. On the left panel, navigate to: Farm_BIDomain > WebLogicDomain > BIDomain. 
3. Click on BIDomain.
4. On the right panel, click on the BIDomain WebLogicDomain drop-down menu on the top left hand corner
5. Navigate to Security > Application Roles
6. On the Applications Role UI Search pane,
7. Select the 'Select Application Stripe to Search' radio button. This will enable the text field for app-stripe.
8. On the enabled drop-down field select the 'obi' value.
9. On the Role Name field enter 'BIAdministrator'.
10. Then select the 'Search Application Roles' go to button.
11. On later versions of Enterprise Manager, the Role's Members are displayed in a list underneath the Role
12. On the detail result section, select the BIAdministrator role name. This will open the Edit Application Role : BIAdministrator UI.
13. In the Add User Dialog search for user log in string
14. Once the user is displayed in the Available users pane, shuffle the user to the Selected Users pane. Then press OK to save the changes. On later versions of Enterpise Manager, search for the desired user log in string, then click "OK".

This will add the user to the BIAdministrator role. Server bounce is not required for changes to take effect.  Instead, this change requires that the ESS job named Retrieve Latest LDAP Changes (formerly SyncRolesJob) be run to synchronize the change from Enterprise Manager in to Fusion Applications.  Please run this job.

For Details with screenshot please check this note 

How To Assign BIAdministrator Role to a Fusion Applications User [ID 1395598.1]

Cheers