First, you should define a "NodeReferenceState" on ModelEntity. After finding the appropriate sink to send use "set node" step to assign the found sink's input node as the destination node of the entity (ModelEntity.NodeReferenceState=input@sinkx). Then, do not use transfer step. Instead, set the entity destination type property of source object as specific and also set node name property as ModelEntity.NodeReferenceState. By this way each entity will find its own way via the links you defined.