Group report is a report where one or more fields are used to group the other fields. Access has such useful feature that helps you to create reports that are grouped on more than one field. So, now you can group a report on multiple fields quite easily using the Report Wizard in Access 2016.
Below here is the complete step to create a report that is grouped on two fields.
Make selection for the fields that you like to appear on the report. You can select fields from more than one table or query.
Select a table or query using drop-down list. After then make double click a field from the left pane to move it across to the right pane. Repeat this for each field which you want to display in the report. Fields present in the right pane will appear in the report.
Repeat this for relevant query/table. After completing all this, click next.