We posted how to configure OBIEE for SSO using SAML and ADFS , on a single node previously --> there: https://blogs.oracle.com/pa/entry/obiee_web_sso_with_adfs
This post describes how to perform the same, but with a clustered OBIEE deployment. The main change is regarding the necessary use of aWeblogic RDBMS security store to cache SAML assertions across nodes, as well as the configuration of the load balancer.