The new XR General Grab Transformer reduces the complexity of the hierarchy and allows one general-purpose transformer to support both single and two-handed interactions on an interactable, rather than multiple grab transformers. It also enables two-handed scaling, letting you scale objects up and down by moving your hands apart or together, similar to zooming in and out on a mobile phone.
We’ve also added an Interaction Group component. This behavior allows a developer to group interactors together and sort them by priority, which allows only a single interactor per group to interact at a given time. For example, when a Poke, Direct, and Ray Interactor are grouped together, poking a button will temporarily block the other interactors from interacting with the scene. This can keep you from accidentally grabbing something nearby when you’re working in the distance, and prevents rays from shooting into the scene while you’re grabbing or poking an object up close.
Source: Unity Technologies Blog