Resolution
It is possible to set up a LDIF connector to split a single LDIF file's entries into two types (i.e. account type and group type) in Identity IQ.
You can define separate filter attributes for these two types (ex: account type and group type) on your LDIF application doing the following:
From the debug pages, add these to your application object:
<entry key="account.filterString" value="!objectClass.containsIgnoreCase("user")"/>
<entry key="group.filterString" value="!objectClass.containsIgnoreCase("group")"/>
The "account" filter will be used during account aggregation, and the "group" filter will be used during group aggregation.