Formular for identifying the relationship between items in the same column

I developed a tool to help our business develop our website. We want to show our clients our Markets and Practice Areas. I have included both types of these in the same table. I would like top identify the relationships between each. For a given Market , we may have numerous Practice Areas. Conversely, for any given Practice area, there may be multiple markets which apply.

For a given Market, I would like to assign all of the applicable Practice Areas. For any given Practice Area, I would to see all of the markets which apply. I can’t seem to develop an appropriate formula.

Why not use two canvas control filters?