If you’ve used Power Query long enough, you’ve needed to group data and provide some sort of summary. For example, grouping by customer and summarizing sales. The normal way the Table.Group function works is to group the entire table by the field(s) you are grouping by, then providing whatever aggregations you need.
However, you can alter that behavior and group data by a column, and have it provide a separate group at each change in the data.
Click through for the rest of the story. There’s some complexity to the problem which is hard to summarize.