buckets property

Determines the bucket from which values are chosen to sort.

For example, in a pivot table with one row group & two column groups, the row group can list up to two values. The first value corresponds to a value within the first column group, and the second value corresponds to a value in the second column group. If no values are listed, this would indicate that the row should be sorted according to the "Grand Total" over the column groups. If a single value is listed, this would correspond to using the "Total" of that bucket.