Posted by Alexander Schwartz on Mar 30, 2020; 8:24pm
URL: https://discuss.asciidoctor.org/How-to-create-a-figure-with-two-graphviz-diagrams-in-it-tp7805p7806.html

Graphviz supports two subgraphs like this:

[graphviz]
....
digraph G {
compund=true ;
subgraph A {
a -> b;
b -> a;
};
subgraph B { rankdir=LR;
1->2;
2->1;
};
}
....

I hope this will get you closer to your goal.