grouping field
For view analysis-style views, the grouping field determines how the view organizes the statistics and data it presents.
For example, if a view calculates the total rentable area in all buildings and organizes (that is, groups) this data by the states in which the buildings are located, the State Code field of the Buildings table is the grouping field for the view.
You may wish to include secondary grouping fields, which organize the data within the parent grouping field. For the above example, you could set Postal Code as a secondary grouping field so that the view organizes the data by state, and within state, by postal code.
When defining a view analysis view, you must specify at least one grouping field and it must be a field that is visible in the view and that is not the table's primary key.