digraph test{

// declare nodes all out of desired order

A -> D;
A -> B;
A -> C;
A -> E;

B;C;D;E;

// even these new connection don't mess up the order
B1 -> F -> G;
C1 -> F -> G;

subgraph cluster_foo{{
rank = same;
edge[ style=dotted];
 B -> C -> D -> E ;
// E -> D -> C -> B ;
rankdir = LR;
}}

subgraph cluster_bar{{
rank = same;
edge[ style=dotted];
// Note the edges going right to left in this cluster; LR order is not enforced
 E1 -> D1 -> C1 -> B1 ;
rankdir = LR;
}}

E -> E1;
D -> D1;
B -> B1;
C -> C1;

}