Split Keys: Shape Key Management
Put together up to three shape keys and display each value in one place. This allows you to group related shape keys for easier management and control over your mesh. An example would be the left and right eyebrow as shape key 1 and 2, while the 3-rd would be both of them together.
Time to bring some order to the huge list of scattered shape keys. And if you want to truly tame that list, then you need the shape key folder management addon: Shape Key Collections - https://blendermarket.com/products/shape-key-collections