Search across multi-server achitecture

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I am trying to use the search feature to discover all recorded entries of a particular attribute. But the company maintains multiple chef servers which all have the potential to have this attribute stored, and I need them retrievable from a single instance.

I've been tasked with installing a product which contains a server install and many client agent installs.
The client agent names are derived from their environment+hostname+sequence in cluster (eg. PR_APP_01), and the names have to be registered on the server side also.
Given the names are derived from the host, I have taken to recording the agent-name as an attribute, so that the server side install can search for all available agents and do the necessary.
The "problem" is that the company host multiple chef servers (to keep distinction between MDM architecture, Integration, Hybris, etc), and a client will be installed on hosts across these.

Is there a way to achieve this without creating a predetermined map of what names I am expecting?
I was hoping to avoid this sort of maintenance.