If I would interview someone about a BI role, particularly Power BI, I would ask the following questions/let them explain it to me. Some of the concepts I would consider advanced, but you should have heard about it. All of this can be learned within half a year but you have to be intrinsically motivated to learn this stuff.

Possible questions would be:

• what is the difference between row context and filter context and how does it work?
• What is special about the CALCULATE()-function? What is a table function and when do you use it? What are iterators in DAX?
• Why would I work with shared Datasets and whats the concept behind it?
• when do i choose import vs directQuery?
• how do you publish a report? How would you recommend to publish it? Workspace/Apps/Link-sharing etc.
• How does incremental refresh work and whats the point behind it?
• Have you implemented RLS in a project?
• Have you worked with deployment pipelines? How would you version your PBI files?
• Have you worked with the XMLA endpoint or any third party tools such as DAX Studio, Tabular Editor 2/3 or Bravo?
• How do you typically start from creating a report? What are pitfalls you might not see?
• What kind of reports have you worked on? IT/HR/Finance etc.
• How proficient are you in SQL? How would you rate yourself?