Where to dispatch multiple actions in redux?

As other pointed out The action creator is the right place for dispatching multiple actions.

Below an example of how action1 could dispatch other actions in your action creator.

const action1 = id => {
  return dispatch => {
    dispatch(action2(id))
    dispatch(action3(id))
  }
}

If you have a Promise Middleware, you can use this syntax so you're able to use .then() on your dispatch(topLevelAction()):

export const topLevelAction = () => dispatch => {
    return Promise.all([dispatch(action1()), dispatch(action2()), dispatch(action3())])
}

The action creator is the correct location for dispatching multiple actions. Although code like the following would work:

function actionCreator(payload) {
    return dispatch => {
        dispatch(action1(payload))
        dispatch(action2(payload))
    }
}

I would highly recommend redux-thunk based action creators to always return a resolved Promise, so that such action creators can be part of another async call. So, the simplest update to the above would be:

function actionCreator(payload) {
    return dispatch => {
        dispatch(action1(payload));
        dispatch(action2(payload));
        return Promise.resolve();
    }
}

It would then be possible to dispatch to the above with: actionCreator(payload).then(doAnotherAction(anotherPayload)) or the following, if we need to maintain order of calls: actionCreator(payload).then(() => doAnotherAction(anotherPayload))

If you wish to 'future-proof' your action creator, so that it could handle calling both async and sync action creators, you could write it as:

function actionCreator(payload) {
    return dispatch =>
        Promise.resolve(dispatch(action1(payload))).then(
        () => dispatch(action2(payload)));
}

And, if you like ES6 arrow notation the above can be defined as:

const actionCreator = payload => dispatch =>
        Promise.resolve(dispatch(action1(payload))).then(
        () => dispatch(action2(payload)));

The recommended way as per the documentation is in the action creator, like so:

function actionCreator(payload) {
    return dispatch => {
        dispatch(action1(payload))
        dispatch(action2(payload))
    }
}

Then you would probably want to attach the action creators as prop and pass it down to the container using mapDispatchToProps like in the example mentioned here. So it would look something like so:

const mapDispatchToProps = dispatch => ({
   action1: some_payload => dispatch(action1(some_payload))
   action2: some_payload => dispatch(action2(some_payload))
})

// your component
export default connect(mapStateToProps, mapDispatchToProps)(YourApp)