Yes there is, the nested stack should have an output of the attribute that you are interested in and the parent template can simply call for that attribute. For instance, this 'parent' has two nested templates, Network and LoadBalancer (both are Neutron resources). The parent will define both like so (Note those are not complete pastes):

resources:
  network:
    type: network.yaml

  load_balancer:
    type: lb.yaml
    properties:
      private_subnet: {get_attr: [network, private_subnet_id]}
      depends_on: network

Now, the network template creates a private network and has this as an output:

resources:
  private_network:
    type: OS::Neutron::Net
    properties:
      name: private_net_heat

outputs:
  private_network_id:
    value: {get_resource: private_network}

As you can see, by creating an attribute called private_network_id and giving it the value of the private network, the Load Balancer template can use it as a parameter for the pool resource:

parameters:
  private_subnet:
    type: string

resources:
pool:
    type: OS::Neutron::Pool
    properties:
      protocol: HTTP
      monitors: [{get_resource: monitor}]
      subnet_id: {get_param: private_subnet}
      lb_method: ROUND_ROBIN
      vip:
        protocol_port: 80