If we were to analyze your example, it would probably be sufficient to note that the following characterize it:
(1) The subgraph induced by $U$ can be **any** directed graph
(2) If we contract all the edges connecting nodes of $U,$ then the resulting graph is a graded directed graph (a specific type of bipartite graph).
Since condition (1) is fully general, I'm doubtful there will be a named class smaller than the class of all directed graphs which you could use to study this type of graph.
Also, note that there is no guarantee that decomposing your graph like I did with (1) and (2) will suffice to prove what you want. You'd also have to prove that whatever you're trying to show is preserved by that decomposition.