board inside board : (preview ) (duplicate ) & (position) every thing from board A2 to board A1#582

for example : i created a board called “A1” inside it i created board “A2”
1) hover on the icon of the board “A2” and see the board preview ,

2) also need “A2” boards cards and file , every thing to be (move/duplicate) inside A1 (with a toggle option ) duplicate means changes to any one card and all duplicate card will change (need history of edits).
3) remember the position of cards inside “A2” if we change the position in A1 and like it (one click option ) and inside A2 cards can change there position, and simillarly by mistake i mess it up (one click and position) goes back