Yes this is possible, i've attached my workbook for you to download if needed.
Firstly i simply created your data source:
Next i brought it into Tableau (twice) and joined it using a Left Join (to ensure the null value is not excluded) with the below highlighted join calculation:
Finally creating the view your were looking for:
If this solves your issue please mark the answer as correct, if not let me know!
You can do this on the data connection screen. Join the data to a copy of itself - let's call the first copy A and the second copy is B. Left join A and B on A's Child field equals B's Parent field. Then in your viz, filter out the Parent rows for AA and BB. It'll give you that second table that you're looking for.
If you have any questions, let me know.