No. This is not possible.
To initiate a call, roaming subscriber would send the Invite to visited PCSCF.
Based on service-route hdr information(stored by this PCSCF during registration), PCSCF would send the request to home SCSCF.
Home SCSCF now would contact HSS to get the caller profiles for this user.
So Hss and Scscf both belonged to home domain.