Information in the Main Grid View of records can be sorted and organized using grouping by Columns .
Drag the header of the column you want to group by to the Drop Columns Here row at the top of the grid. For example, to group Organizations by State, drag the State column header 
and drop into the Drop Columns Here row.
Sub-groupings can be achieved by dragging and dropping additional columns.
Groups are retained when you navigate away from the page. To remove a group, click the X in the grouped column’s label.
For additional information about Grid views, click the Create a New View, or Views link.