Mapping jOOQ join result into multiple POJOs

Say you have a query with multiple joins:

    db.select()
        .from(A)
        .join(B).onKey()
        .join(C).onKey()
        .fetch()

How can I fetch this into a Map<A_POJO, List<Map<B_POJO, List<Map<C_POJO, List<D_POJO>>>>?

I know there is fetchGroup, but I'm not sure it works for more than one join?