Cumulating Objects in the Configuration Folder 
If you want to create a Baseline, then in principal it is normally enough for you to just have entered the controlled object in the configuration folder. When creating the Baseline, the system automatically completes the structure provided you have flagged the relevant objects appropriately.
You can still enter other objects in the structure of the configuration folder, such as when you want to expand objects that are not part of a BOM and for which no object links exist.

When the controlled object is a material, assign a document info record with a specification to it for example.
Do not assign another material to a material that is a component it it’s BOM. The system automatically determines the components from the BOM.
See also:
Indicating the relevant objects. Automatic Completion of the Structure