This button folds a level of lines: phases and projects. Only breaks will be visible, even though everything is folded. This button is accessible from the timesheet header line on the left.
Allows you to fold a level on the board: fold project phases, or fold phase resources, for example.
Allows you to fold a level on the table: fold the risks of a severity, fold the severities of a type of risk.
At the top of plan : Allows you to collapse a level in the plan : collapse project phases, or collapse resource projects, for example. In the plan , at the resource level: This button allows you to expand all lines for the resource: projects and phases.
This button is accessible from the header row of plan , on the left AND at the resource level using the chevron.