When using commands in Minecraft Java Edition (e.g. /fill), before opening the chat window I normally just have to aim the crosshair to a block, then open the chat window and type in the command. Now when I press the Tab key 3 times, Minecraft auto completes the coordinates of the aimed block itself.
However this does not seem to work in Win 10 edition. Am I doing something wrong here or is this really not possible there?