I am saying if there is any feature to limit the number of subcat levels that display under a parent category it would be in the category manager in admin for vbgallery. Our Pro series has alot of functionality vbGallery does not.
I am not saying there is any such feature in vbGallery. Just because you want something to work a specific way does not mean its going to work that way. If there is no setting in your vbgallery admin panel to limit the number of category levels to display then there is no way to do that.
You can also place a url to explain what you mean. The members gallery should categorize users by username right. You click that category and you get all albums photos etc.