Fetching Global Chat History on Spark

Hi,

I am customizing the Spark UI as part of my project, and I want also to take control on fetching the group chat history from Openfire.

I have downloaded spark source code and I got how Spark fetches the One-One chat history,

but I did not find the place where the Spark fetches the Group chat history.

Could you please help me in this regard?

Thanks, Venu