You can create a control that allows you to pick and choose which columns/rows you want to show on the dashboard:
Сlick the 'control' icon and create a new control
Drag and drop the variable to 'Drop here'
Choose 'As list'
Rename the control name
Change the control type to Option groups.
Change the selection mode to Multiple.
Tick the checkbox of each option to switch them on.
Click 'Save control'.
To assign this control click on it and then hover over the widget you want to assign it to.
Select Put on: Columns/Rows. This will populate the columns/rows of the chart with the variables that are in the control.
Switch to the VIEW mode to see how the control works live.