Virtual MPI Topology Topology

I have the following problem:

I would like to create a virtual topology based on a tree graph, for example:

   0
 /   \
1    5
| \  | 
2  4 3

The number of vertices is a series of processes.

I managed to do this, and I have a handle to my new communicator:

MPI_Comm graph_comm;
MPI_Graph_create(MPI_COMM_WORLD, nnodes, indexes, edges, 0, &graph_comm);

Now my question is: Is it possible to send a broadcast (MPI_Bcast) from each of the parent nodes that have children only for their children (in this example, a process with a rank of 0 sends bcast to processes 1, 5, a process with a rank of 1 sends bcast to processes 2, 4, a process with a rank of 5 sends a bcast for processing 3)