Doubling

I am new to the group and would first like to express my gratitude for all the resources and particularly all the videos going through the Music Code. I found the video on “All About Dot 3” so useful in pulling together information. I would find something similar that addresses “doubling” very helpful. I find myself getting a little sketchy on doublings, particularly triplet doublings in keyboard music–when they need to be restated or not, used or not used, and if there are differences in single line format vs. bar over bar.