How to set a multi-level approval flow for purchasing module after creating user groups?

• Go to “Settings”
• Click on “Multilevel Approval Settings”
• Click on “Add new module” 
• Select “Purchasing” and click on “Add”
• Click on “Add New Rule”
• Select the “Department” from the dropdown menu (allows multi-selection)
• Select the “User Group” from the dropdown under the levels
• Click on “Add Level” to add multiple approval levels (Maximum of 5 levels are allowed)
• Click on “Submit”