+ / - above column letters

[Guest]

I saw a spreadsheet that had some plus and minus buttons above the column
letters that allows for the columns under them to expand and collapse when
clicking the buttons. How do you do that?

 

[Guest]

select a contiguous set of columns or rows and goto <data><group and outline>
and select group
also check "outline" in help

 

[Guest]

Select the columns, then Data->'Group and Outline'->Group