What are you needing to know? I'll be glad to answer any questions you may have
. It's a simple Joomla search plugin so it doesn't really have any documentation. All its functionality is self contained in Extensions > Plugins while editing it (should be named "Search - Community Builder").
It does not work with Joomla's smart search as their indexer doesn't let us apply our more complex access permission checks (without these checks profiles could display that are set to private!). On Joomla 4 for new installs to use the legacy search you've to manually install their legacy search component since it was removed.
We'll be trying to workaround the smart search limitations in a later releases, but it's unlikely we'll be able to. It's best to use a userlist to search users.