One way to achieve this to create 2 charts with one with Date Dimension and other with Countries dimension. And then you can show and hide the charts as per sheet activation.
You can can use a variable to dynamically shift dimensions.
Create a variable and set its value on sheet activation.
Like varTest = 1 for sheet SH01 and 2 for SH02
then in the chart you can use, IF statement in dimension.
If(varTest = 1, DATE, Countries)