title: Task lineage between Dependant Dags in Airflow
body: <p>We have many DAGs scheduled to run daily using <strong>Airflow</strong>. Dependencies has been enabled using ExternalTaskSensor, TriggerDagRunOperator and custom operators</p>
  
  <p>Sample:</p>
  
  <p>Task 1 in DAG A are dependent on task 2 in DAG B<br>
  Task 3 in DAG A are dependent on task 4 in DAG C<br>
  Task 5 in DAG A are dependent on task 6 in DAG D<br>
  ...</p>
  
  <p>Task 2 in DAG B are dependent on task 7 in DAG E<br>
  Task 4 in DAG B are dependent on task 8 in DAG F
  ...</p>
  
  <p>While checking Task Instance details in UI, only downstream_task_ids and upstream_task_ids belonging to the same dag are displayed.</p>
  
  <p>How can we see the full lineage of a single task across multiple DAGs to the last available level?</p>