Can someone please provide me with an example of Level 1, 2 and three of business processes in AX? How I can map them with Epic, Features, requirements and tasks?
You'll find a plenty of examples in process libraries of Business Process Modeler in LCS.
You forgot to mention it, but I assume you're talking about mapping to work item tracking of Azure DevOps. If so, look at Synchronize BPM libraries with Azure DevOps. Also note that requirements and tasks are not business processes - there are pieces of work you need to do to support business processes. For example, you identify a gap in your business process, create a requirement to fill the gap and add tasks for various people to design, implement and test the solution.