Grouping tasks in a non-date-driven order on a Timeline report
In the Tasks table there is a numeric field named Sort. This is to sort the tasks in a desired order. Ideally we would use the start date to sort but for this particular use case we need to have the tasks in a specific order.
In the Sub-tasks table the Task and Task Sort fields are lookups. I'd like to have a gantt chart, grouped by Task Sort and Task, and then sorted by Sub-task. When I do this with the current set up the the grouping shows as in the first image below. I want the Sort and Task on the same line, like in the second image.
I've done things like this before with automations and actions, where I've had multiple choice fields that are 'sort in this order' and I use an action to fill in the multiple choice field based on the related Task. But it's not a user-friendly solution because every time a task is added, you'd have to add to the multiple choice field. I tried creating a formula to string the values together but then the tasks come through in 1, 11, 12, 13, etc. order because it's being read as a text field.
What are all your best practices for grouping tasks in a specific non-date driven order?
The second image below I edited for example.
Current situation:
Ideal situation: