I remember watching a tutorial where the user had a rigged model and selected a pose in the pose library and then was somehow able to click and drag on the thumbnail in the Asset Library to partially apply the pose. So if the pose Asset was a clenched fist and the rest pose was an open hand, they could open and close the hand by clicking and dragging in the pose library.
How do you do this? I can’t remember what I need to do to activate this.