Setup: standalone root, domainjoined subordinate CA
Target: remove the Domain Component (DC) from the subject in the subCA's certificate
Solution: while configuring the subCA ADCS role, the DC is automatically filled with the current domain information. So that becomes "CN=hostname,DC=domain,DC=location". To remove this, simply enter a space for DC info, so "CN=hostname,DC= , DC= ".
On a standalone machine you can simply keep it empty