Thank you for your answers.
For the second question, I know I can set that only the Manager can approve a LR, and it is good to hear the new features, but I feel like I didn’t get the correct answer. Maybe my example was bad so I try another:
I have two managers: John and David. John is a DEV Manager and David is a Marketing Manager. When an employee from DEV Department request a Leave, I want only John to get the request, but they both get it. I want to John only gets the Dev requests and David only gets Marketing requests.
I hope the problem is more understandable now.