Here is an answer to the Question asked on KnowOracle Blog about Personalizing the Oracle HRMS Employee Directory to add additional Phone Numbers for Employees.

Here is the PDF Document for Employee Directory Personalization that explains the following steps with screenshots.

The Employee Directory: Before Personalization for Phone Numbers:
Click On “Personalize Page” link:
Select the Phone number you want to Display. You can set the initial Value “W1” to another value as you desire, and then Prompt can be modified too. Lastly, Rendered should be changed to “True” at site or responsibility level as per your requirements. W1 is default Oracle usage for Work Phone. Hit Apply, and return to Application.
And you can see, the phone number will appear as desired.