According to https://docs.unrealengine.com/latest/INT/Engine/Animation/RetargetingDifferentSkeletons/?utm_source=editor&utm_medium=search&utm_campaign=user_initiated (which seems to be for an older version) under the “Retargeting Adjustments” section, it says that there should be a “Recursively Set Translation Retargeting Skeleton” in the context menu when right clicking on a bone in the Skeleton Tree, but it’s not there (at least not in 4.15). Was it moved somewhere else?
Ok, so turns out that there is a step missing in the documentation.
In the bottom right of the Skeleton Tree, you have to click on the “All Bones, Active Sockets” and check “Show Retargeting Options”. Only THEN does “Recursively Set Translation Retargeting Skeleton” show in the context menu when right clicking on a bone.