I'm likely approaching this issue from the wrong angle, please tell me if I am.

Our setup is as follows
* We have Staff, Students and Parents as objects in our eDir
* We will have several SAML 2.0 SP configured, currently we just has the TestShib one configured
* We also have our School Management System (SMS) which we want Parents to access.
* I have configured 2 different User Stores, Methods and Contracts, one of Staff and Students, another for Parents.
* There is a third contact setup to allow Staff and Students to sign in with Google, as we use Chromebooks this save them retyping their username/password
* The Parent login page is different as we need their listed email address and firstname for a sign in, this is because 2 parents could have the same email address.

That is the basics of the setup, what I want to have is
* When logging into the SMS, all 3 contracts are available in the selection.
* When logging into the IdP for a SP, only the Staff and Student contracts are available.

Is there a way of doing this? Am I approaching the problem from the wrong viewpoint? I was initially thinking we could have something like "Only these contracts available" that could be configured in the SP config.

This is with a AM 4.2 appliance.

Thanks for any help.