When you generate the resource map it will use the Affinity layout by default. Once it’s been generated you can then switch to the "Tasks" tab and click "Gantt View". Doing so will change the resource map into a Gantt chart, with each of your resources forming a summary task.
Any task information you had assigned to branches in your map will not have been preserved however, so dates and other task data would need to be added after changing your map to the Gantt view.