Filtering a Chain of Tables by Selecting Table Rows

Hi, WZorn 

You might want to try implementing cascading filters in your table. Cascading filters (also known as hierarchical filters) are when making a selection on the first filter causes the second filter to be limited to the values that are now relevant. This setting is often used to provide only relevant data values to the user for better performance. You can check the follwoing link:

Cascading Quick Filters in Tableau - The Information Lab

In your example, when you select a state in Table A, it should filter the counties in Table B. Then, when you select counties in Table B, you should filter the cities in Table C. However, the selections in Table B should not clear the selections in Table A.

The problem you are facing may be due to the way the interactions between tables are set up. The selection in Table B may have reset the filters in Table A in some way. Without understanding the specifics of the setup, such as the software or code you're using, it's difficult to provide a precise solution.

However, there are resources that can guide you on how to properly implement cascading filters. For example, if you're using Tableau, you can use a comprehensive tutorial. If you're using Power BI, there's also a tutorial on how to use cascading filters:

Tableau Filters - Comprehensive Tutorial including Context Filter, Cascading Filters | sqlbelle (youtube.com)

Cascading Filter in Power BI Tutorial (47/50) (youtube.com)

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Best Regards

Yongkang Hua

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