Creating Mapping for Sub Identities with no Main Identity

Can you clarify a bit? I assume you want to link UNSAccountB to its relevant Person object? Do you have the matching rules to link the two?

I will need to create the main identity first, currently it does not exist, and from there match to its relevant Person object. I do not have the matching rules to link the two. I was looking around for any documentation, but thus far have been unsuccessful.

I would consider the Person object as the "Main Identity" :)

The system cannot automatically link the UNSAccounts to the Person objects without the matching criteria. If you have the criteria, you can use it in the data importer itself which means when you import the data it will automatically link it to the person object.

E.g. In your target system you store the user's email address which you want to use to link to the Person object. In Data Importer, all you need to do is match the email column to FK(UID_Person)->DefaulEmailAddress and then when you do the import the UID_Person field should be populated with the Person object's UID.

HTH

Aarav