Hi @Alfredo Revilla (Personal Account) · Thank you for reaching out.
Here is a sample to perform Home Realm Discovery to bypass the Unified Signup/Sign page: https://github.com/azure-ad-b2c/samples/tree/master/policies/default-home-realm-discovery
Policy files can be configured with default technical profile, which can be the Technical Profile for local account signup.
You can configured the policy to redirect the users to a specific IDP based on domain hint, the value of which will be picked from email suffix. E.g., if user@Company portal .com is signing in, the domain hint parameter will be set to contoso.com and user will directly see the contoso IDP's auth page. User with user@Stuff .com will directly land on google's auth page. However, if a user enters user@jaswant .com and abc.com is not federated with B2C, the Default Technical profile will be invoked, which will present the user with sign-up form.
Note: Users enter their email on a webpage of the web apps in this case rather than on the Signup/Signin page.
-----------------------------------------------------------------------------------------------------------
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.