You can start three different topologies but use the same callback module for each of them. Something like

defmodule MyBroadway do
  use Broadway

  def start_link(queue) do
    Broadway.start_link(__MODULE__, ...., queue_name: queue)
  end
end

and then in your supervision tree:

children = [
  {MyBroadway, "queue-1"},
  {MyBroadway, "queue-2"},
  {MyBroadway, "queue-3"}
]

If you want them to be consumed precisely from the same topology (let’s say because you need to share batchers), then that’s a feature that yo need to add to your producer.

Jose’s example is a simplification. You have to give a different id for each supervised process (like described in the error message) and a different name when calling Broadway’s start_link/2. You can do both at the same time by defining a child_spec function in the module you use Broadway.