Content Library content suddenly missing

I had a scene opened and while I was working on it, everything in my Content Library went missing. I have no idea how this happened. Perhaps I hit something by mistake. I cannot figure out how to get it to show up in my Content Library. Anyone have any suggestions?


Screenshot (1).png
1600 x 900 - 117K
Comments
Above "None" and below the search box in the middle of the bar there are two rectangles - click the lower one to re-expand the folder list.
Thank you, Richard Haseltine. I probably would have never noticed those two rectangles. I thought I somehow deleted all my content. Boy am I relieved that that didn't happen.