If the “Single line mode” option is not selected (tick removed), a column header "Use your mouse to pull a column here to group on that column" will be displayed and the similar data in columns can be grouped.

Group columns

Select a column and click on it. While holding the mouse button down, drag it to the column header bar "Use your mouse to pull a column here to group on that column". Select any other column to drag and drop it on column header bar. You may select as many columns, as necessary, to group your data.   

You may also drag and drop these columns to the right or left to change the grouping of these columns. 

Remove grouped columns

To remove a column from column header bar "Use your mouse to pull a column here to group on that column", you may use the following two (2) options:

1. Select the column heading (e.g., “Stock group 1”) on column header bar "Use your mouse to pull a column here to group on that column", and drag it to the first line (above the column headings). When the mouse pointer change to a big X, drop it. The column will automatically be placed in the correct default sequence (or the place of the previous grid layout). 
2. If you wish to change the column to a specific place, select the column heading (e.g., “Stock group 1”) on column header bar "Use your mouse to pull a column here to group on that column", and drag it to the second line (column headings). When you drop it, the column will be added to the selected position or sequence of the columns.