As I see, you are trying to programmatically access the names of all signals aggregated at different "Bus Creator" blocks. To perform this you could use "find_system" function as follows :
busCreators = find_system(bdroot, 'BlockType', 'BusCreator');
The above command finds all "Bus Creator" objects at various levels within the model. By default "find_system" searches at all levels for a "BlockType". The names of input signals or any other properties can be accesed using the "Handle" as followes:
busCreatorHandle = get_param(busCreators{1}, 'Handle'); %first busCreator object
signalNames = get_param(busCreatorHandle, 'InputSignalNames');
For more information on "get_param" and "find_system" functions, refer to the below documentation links:
Hope this helps!
