The ability to access and modify the "SelectionChangeFcn" property in the Property Inspector of GUIDE is not available in MATLAB.
The automatically generated callback function can be accessed by right-clicking on the Button Group panel and selecting "View Callbacks > SelectionChangeFcn".
If you would like to modify the SelectionChangeFcn, you will need to GET the property of the Button Group graphics object as follows:
get(H,'SelectionChangeFcn')
and similarly you can SET it by :
set(H, 'SelectionChangeFcn',<VALUE>);
where, H is the handle to the uibuttongroup and {VALUE} should be replaced by the MATLAB code or a handle to a function that you desire to be executed when the selection change occurs.
