A data source can be assigned to multiple policies. If you need to view all the policies for a data source, you can do so from the Data sources grid.
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Click Govern in the navigation menu on the left.
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Click Data sources.
Click the ellipses (…) that display when you hover at the end of the row for the data source.
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Click View policies from the menu that displays.
You will be taken to the Policies page, and the grid will be filtered to show all the policies to which the data source is assigned.