As far as I know, the "View Sensitive Data" privilege is "hardcoded" to these three data domain groups.
The ability to map other Data Domain Groups to this privilege is a new feature request (happy to be corrected).
A workaround is to create other Data Domain Groups in line with your requriments and add the data domains of interest into one of the PII / PCI / PHI groups to restrict access. To address any user confusion, you could probably create an intranet page / internal wiki page or other documentation justifying the addition of non-PII/PCI/PHI data domains into the PII / PCI / PHI groups.
Please feel free to raise a ticket with Informatica Support to get a feature request raised for this.