The predicate named shibboleth.Conditions.RelyingPartyId provide a simple mechanism to make decisions based on the entityID of the relying partym
Is an activation condition, which means that is can be automatically configured as an activation condition, this also means it can also configured anywhere that a ProfileRequestContext is supplied as input.
These are abstract beans and so your version has to be appropriately constructed. They are usually constructed with a single parameter, being the list of predicated to be consulted, but as a short a two parameter version allows you to provide exactly two parameters,
Examples
Examples can be found here