Matlab/simulink + model advisor

I have customised top-level block library and sub-library linked to the top-library block for my model. My intention is to check the names of blocks within the sub-library block . How can i get the list of blocks from the sub-library?

with the following code , i can have all reference blocks from my model to aboth libraries( since there is direct link from my model to top_level library as well) but i want to look at the sub-library blocks only.

 system=bdroot;
 blocks = find_system(system,'FollowLinks','on',...
                            'LookUnderMasks','on',...
                            'LinkStatus','resolved');
refblocks = get_param(blocks,'ReferenceBlock');