Yes, ordering of dimensions is very important. The report will be generated based on the order of selected dimensions. Suppose, you want to generate a report of region wise cost for each of the Linked Account. You can select dimensions in 2 different ways.

Case 1:      Dimension 1: Region
                  Dimension 2: Linked Account

This will generate a report with Region as first column and Linked account number as second column. This way, you will be able to get linked account cost, based on all the regions.

Case2:      Dimension 1: Linked Account
                  Dimension 2: Region

This will generate a report with Linked Account as first column and Region as second column. This is the correct way to generate a custom report of having region wise cost of each linked account.

So, based on the view you want to create in the custom report, you need to order the dimensions.

Did this answer your question?