My Library Screen is not showing me all of the subfolders I've created in Windows File Explorer

I have an external 20T hard drive attached to my PC.  On that drive are top level folders by YEAR eg. "2015." Included in the list of top level folder are many subfolders, some that read "2015-02-19" for example and others that read "2015-02-19 Tulip Gardens"   Lightroom is only showing me the subfolders that have just the YEAR-MM-DD as a subfolder name.   I'm trying to import everything in my top level folder "2015" but all I get as a result of my imports are the subfolders designated with YEAR only. None of the other subfolders show up.  WHY?  Thanx!