"OpenCloseGroup"

"OpenCloseGroup" is a front end token that opens selected groups if they are closed or closes selected groups if they are open.

This token is equivalent to the menu command Cell Cell Grouping Open/Close Group.

This token will affect only the outermost level of selected groups.

To execute a front end token, you typically evaluate a command of the form FrontEndExecute[FrontEndToken[token]].