Position Hierarchies

Hi,

Need your suggestion for requirement below:

I have 3 users (A,B,C) and i want to separate the approval based on document total and item category range

Types 1:

1. User C: Document total limit 5,000,000 & item category range include (low-hi): Goods

2. User B: Document total limit 10,000,000 & category range include (low-hi): Goods

3. User A: Document total limit 15,000,000 & category range include (low-hi): Goods

Types 2:

4. User C: Document total limit 50,000,000 & category range exclude (low-hi): Goods

5. User B: Document total limit 100,000,000 & category range exclude (low-hi): Goods

6. User A: Document total limit 150,000,000 & category range exclude (low-hi): Goods

For the requirement above, i use position hierarchy (user A -> user B -> user C) and try to create 2 approval groups and assign it for each user and still failed