Custom Dimensions can be used as Primary dimensions in Custom Reports and Secondary dimensions in Standard and Custom Reports. All of the above statements are true for the usages of custom dimension.
- Secondary dimensions in Standard reports
- Primary dimensions in Custom Reports
- Secondary dimensions in Custom Reports
- All of the above
The correct answer is: All of the above
Explanation: If you are creating a custom report, you can use the custom dimension as a primary dimension. Whereas in the standard report, customer dimensions can be used as a secondary dimension or as a segments.
Google has declared in its official study material that Custom dimensions can appear as primary dimensions in Custom Reports. You can also use them as Segments and secondary dimensions in standard reports.
Read more here: https://support.google.com/analytics/answer/2709828
custom dimensions can be used as what?