digraph dag {
    graph [nodesep=1.5, rankdir=BT];

    Base [shape=plaintext, height=.1, fontsize=24];
    Derived1 [shape=plaintext, height=.1, fontsize=24];
    Derived2 [shape=plaintext, height=.1, fontsize=24];

    Derived2 -> Derived1;
    Derived1 -> Base;
}