Automatically Save "Folder Name" to photo metadata/tags in that folder?

QUESTION: I'd like to have the "folder name" where an image is saved in LRC included as a tag/metadata in each image automatically or thru some bulk action.

BACKGROUND: I have all of my images stored on a hard drive in folders that are named with Date and event.  Hundreds of folders within folders and over 100,000 images.  These folders and the images inside them are then sync'd with LRC.  Using LRC face recongnition, I tag each image with the names of the people in the image. I then write that metadata back to the file to make sure that it always stays with it.  I would love to also save the information contained in host folder name to each image because it relates to the overall event.  With hundreds of folders within folders, i'd love to do this automatically or using some type of bulk action rather than folder by folder or image by image.

Screen Capture Below?