The settings on this screen allow you to customize the the dropdown menu and the designations for the search IDs pertaining to end-users.
See the user-search example below on the User Browser page.
After implementing the modification for the Profile ID label as stated below.
As you can see, there are four distinct categories available for the organization of these user-search IDs.
Default - Must and can only set one default ID. When selecting another ID as the default search ID, the previous one will be switched to the Primary List.
Primary List - Define the primary search IDs to be displayed in the dropdown menu of the user search function.
Others - Define the other search IDs in the menu's Others division. Those IDs could be used less frequently than the primary list ones.
Hide - Hide these search IDs from your search menu to simplify the portal by selecting those IDs that don’t make sense for your app (i.e. there is no need to be able to search by PSN ID if your app does not support Playstation!).