How does top_level parameter govern data in Engine_Branch_List?

Hi

In DM 12.2.6, I have set 7 forecast levels in the forecast tree (Batch mode), as a result of which parameter value of "top_level" got updated to 7. However, there are no records present in table Engine_Branch_List.

With this background, need your inputs of below queries:

1. Is 7 a correct value for parameter top_level?

2. If we want to modify this value, should we update it via DML?? Modification via BM is disabled.

3. What is the significance of every column in Engine_Branch_List?

  Branch_ID -

  Branch_Status -

  Item -

  Location -

  IU_Last_Date -

4. How are top_level engine parameter and Engine_Branch_List table related?