Home Realm Discovery - Customization

Is there a way to modify how home realm discovery works. Currently, if I set up a SAML connection and setup the domain to xyz.com, any user with that domain will get routed to that IDP. However, we have a use case where some xyz.com users may use that IDP, and others will want to login using username/password, or even another IDP. Our user structure does this by referencing a higher level account assignment, to resolve the IDP.