Audit log analysis with PowerBI

I'm trying to use Power BI Desktop to analyse O365 audit logs. In it simplest form I have this cracked.  But I'd like to expand my analysis to included the ExtendedAttributes data, which is effectively json, within a json, within a csv file.  Has anyone done anything with this? 

I think what I am aiming for is a single record per operation, with all the extended attributes linked to this single record.  All I can do at the moment is have multiple records per operation, each record having one of the extended attributes.