The simple way to achieve this task is to "Self-Join"
I would self-join the data again with Inner join on Region and Era
then, to handle the duplicate rows I would create a calculation
[Empire_Data1] = [Empires_Data2]
and put as false in the filter shelf.
then if you drag both Empires field you will the output you are looking for,
Since this is like 20 rows of data, you can perform a self join without any challenge.
But you have a lot of rows as in hundreds of thousands or more then, you might want to prep your data before connecting to the tableau.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…