Note: This has to be done by an app manager or user with the appropriate permissions.
To turn on/off visible fields in user profiles:
- Click on your user profile image in the upper right hand corner and click Application settings > Application.
- Go to People > Provision & sync users.
- Check the box next to the fields you want to display on user profiles. If you make a field visible, you can select whether you allow user to edit the field.

All visible fields are searchable.
Note:
If you synchronize a certain field with Workday or Okta, users cannot edit that field.