Our current set up with Power BI is to host Analysis Services databases, and point a Power BI report to that. Due to the de-coupling of the data model and the report, there is no current mechanism to identify what fields and tables in Analysis Services are being used by which Power BI reports.
I’ve written a PowerShell script that will help in understanding this relationship: https://github.com/avinmathew/extract-powerbi-fields
Point the script to a directory containing Power BI .pbix or .pbit files, and the script will iterate through each of the reports, open up the
Layout file, and extract all used fields to a CSV file with three columns: Field, Table, File.
Due to the complexities of Layout structure with filters on visuals, I’ve taken a shortcut and used regex rather than JSON navigation to mop up any missing properties not found the the first two passes. This will result in the Table column in the CSV file being blank in these cases.