3D array handling is not much different from 2D, you just have another coordinate to specify - "page" (row, column, page). Create a 3D array constant and wire it to e.g. the replace function and it will automatically scale up to show you the index and length options involved...
PS. If you have XY arrays why not just have a 1D array of XY sets (as one would use for multiplot XY graphs)?You could even write the whole array to a graph (save you the extraction operations) and then choose to see whatever combination you would like by setting the color of the plots you want to hide to transparent.