Kasper de Jonge uses Power BI to figure out which columns are being used in an SSAS Tabular model:
I got an interesting question about being able to figure out which measures and columns are being used for all tabular models in a server, either by known reports or by self service users using Power BI. To solve this I decided to use Power BI :).
To get the required information I decided to capture and parse the queries being that are being send to AAS and parse the results Power BI desktop over a period of time. In this post I describe how to do it.
Check it out, and also read the comments for an additional tip from Bill Anton.