Ability to organize playlist in Library.

Right now there is the ability to organize material in a playlist. The problem is once you create a playlist you can not move the playlist itself. Unit 1 playlist material is not altogether and I would like it to be altogether. I have created Unit 1 Week 1 and Unit 1 Week 2 and so on for all the weeks, but depending on when they were created they are not together. I would like the ability to move the playlists around just you can inside of the playslist. This would be very helpful when finding material.