ADFS 3.0 improves user experience With a long wanted feature:
Improved user experience for home realm discovery –AD FS now supports home realm discovery by looking up organizational account suffixes that a claims provider supports or by looking up the claims provider list that is configured for a relying party trust. AD FS also supports by-passing home realm discovery for intranet Access.
This means you no longer need to manually choose which Identity Provider to use when you have different Identity Providers based on different Trusted Relaying Parties by configuring a specific Identity/Claims Provider for a specific relying party trust.
You can also lookup a specific UPN-Suffix and configure that for a specific Identity Provider. Meaning some users can use Active Directory as Identity Provider and others can use other configured Identity providers.