Multi-Department/Multi-Approver Approvals

All - I have a complex requirement for approvals that I need help with.  The client has multiple approvers in many of their County Departments.  There are 33 "Departments" in total. The departments are Level 1 of 4 Levels.  Employees are assigned to Level 4, which are called "Cost Centers".  The organizations from level 1 to 4 are maintened in an Organization Tree.  HR Transactions in the 'field departments' are handled by "HR Liaisons".  If the HR Liaisons enter the transaction, then the approval has to go to their 'Department Approver', of which there may be 2 or more.  If