A rather complicated way to do this would be to create a variable. Create 1 button that sets a value to the first variable, lets say 'A'.
Create another button the does the opposite, setting the variable to 'B' .
Change the Show conditional of the buttons. For the first button tell it that $(variable)='B'
The second button would say $(variable)='A'
(Click the button to set the variable before so you do not have to track down the buttons if the variable='')
Now do the same to the charts. Conditional show based on the value of the variable. First Chart $(variable)='A'
Second Chart $(variable)='B'