Item Sets in the new Beta Client

I have been using the new Beta client interface, and for the most part I really like the new set up. However I noticed that I can no longer create my own Item Sets. This is something I always enjoyed doing in order to cut down on time searching for items. Whether this is an oversight, an in-progress system, or that it was deemed unnecessary, I feel like we should still have that as an option. I didn't know where else to give my feedback, hence this thread.

If there is a way to do it, and I have just overlooked it somewhere, please let me know. Thanks!