At the moment only an one-hop replication of documents to all neighbors is implemented. Therefore all nodes store replicated content from neighbors locally. Instead of one-hop there are many strategies (for example with a parameter for the replication rate) imaginable, but not yet implemented. Feel free to implement them yourself if you want to use it.
As entry point you find the implemented strategy in the class de.tud.kom.p2psim.impl.overlay.gnutella.gia.OneHopReplicator.