If I understand correctly, there is a need to blend or join a data source on the common key of Data identifier as per the example above.
I would first read this article about deciding whether a join or blend would be of best use for the issue at hand: Deciding Between Joining Tables and Blending Data | Tableau Software
Then the below product helps and tutorial should help with implementing the solution chosen.
+ I believe this online tutorial : Data Blending and Data Integration would be of great benefit to watch.
+ As well as this product help on data joins: Joining Tables
Feel free to respond with any additional questions or concerns. I have also attached a sample data joining workbook to this post.
Sample Data Join.twbx 24.8 KB