You can have a variable to check which button is clicked.
Then you compare the variable and show the corresponding layer.
Example:
Global variable layerDisplay
If layerDisplay = 0 => Layer Main Visible, Layer About Invisible
If layerDisplay = 1 => Layer Main Invisible , Layer About Visible
If Main clicked => layerDisplay = 0, Go to Layout TitleScreen
If About clicked => layerDisplay = 1, Go to Layout TitleScreen
How do you call a ayer by name?