According to Walter's comment, the previous solution was wrong. Here is a way to sort B given the sorted A along the 3-rd dimension:
m=3; n=4; o=2;
A=randi(9,m,n,o)
B(:,:,1)=[1,11,111,1111;2,22,222,2222;3,33,333,3333];
B(:,:,2)=[4,44,444,4444;5,55,555,5555;6,66,666,6666];
[~,ix] = sort(A,3,'descend');
[C,R,~]=meshgrid(1:n,1:m,1:o);
lix = sub2ind([m,n,o],R,C,ix);
B(lix)
Looking for a more general solution...
