Network Mobility (NEMO) can ensure continuous connectivity for an entire network and manage the mobility when a mobile router of the mobile network changes its point of attachment to the Internet. However, nested structure of NEMO has its weakness in route optimization (RO) even it does expand the communication coverage. Although recent RO solutions for nested NEMO partly solve this problem, they also suffer various limitations. This work analyzed the structure of nested NEMO and proposed a new route optimization project for nested NEMO. Only by modifying mobile routers and sending the location of top-level mobile routers to correspondent nodes can this method can be used to provide optimal routes. Performance evaluation shows that the proposed method is superior for its lower packet overhead.