DOT graph from superstate to substate

Question

I'd like to generate the DOT code to draw the equivalent state machine diagram shown. I going to be created programmatically, I've got the transitions between states and superstates done. ButI need a bit of help with this:

This gives me an initial transition, but the State1 should be the cluster:

digraph {
compound=true;
node [shape=Mrecord]
rankdir="LR"

subgraph clusterOpen
        {
        label = "State1"
        State2
}

State1 -> State2 [style="solid"];
 node [shape = point label="" ] i ->State1
} 

Answer 1

Normally Graphviz programs try hard to avoid placing nodes on top of other nodes. But you can place nodes anywhere you like if you explicitly provide a pos attribute for each node (see https://graphviz.org/faq/#FaqDotWithNodeCoords).
The program that creates your input files should calculate a pos attribute for each node. (Remember that pos coordinates are in points, while node sizes are in inches!). You can probably skip calculating the splines for the edges and just let neato do that.
This program:

digraph {
    graph [bb="0,0,482.8,337"];
    node [label="\N"];
    State1   [height=4.0139,
        label="{State 1|\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n}",
        pos="162,144.5",
        shape=Mrecord,
        width=4.5];
    State2   [height=1.3333,
        label="{State 2|\n\n\n\n}",
//      pos="403,144.5",
        pos="220,88",
        shape=Mrecord,
        width=1.6944];
    xp3  [height=0.05,
        label="",
//      pos="429,331",
        pos="0,194",
        shape=point,
//      style=dotted,
        style=invis,
        width=0.05];
    r1   [height=0.16667,
        label="",
//      pos="455,331",
        pos="154,194",
        shape=square,
        width=0.16667];
    xp4  [height=0.05,
        label="",
//      pos="481,331",
        pos="0,88",
        shape=point,
//      style=dotted,
        style=invis,
        width=0.05];
    xp1  [height=0.16,
        label="",
        pos="162,331",
        shape=point,
        width=0.16];
    xp1 -> State1:n  [pos="e,162,288.5 162,325.23 162,319.09 162,308.89 162,298.63",
        style=dashed];
    xp2  [height=0.16,
        label="",
//      pos="403,331",
        pos="220,194",
        shape=point,
        width=0.16];
    xp2 -> State2:n  [pos="e,403,192.5 403,325.19 403,307.39 403,251.8 403,202.57"];

// manually added:
  xp3 -> r1      [label="Trigger 1" dir=none ]    
  xp4 -> State2  [label="Trigger 2"  ]    
}

Run with this command line:
neato -n -Tpng stateDiagram.dot >stateDiagram.png

Produces this graph: