Dear Saravana
the screenshopt you have shown is the "most" important one. But you need to check in customizing as well the "environment parameters". Here you have some F1 helkp by SAP; and you will get an idea about environment parameters as used in BOMBOS transfer.
Shortly: If you check the help of activity "Bill of Material Transfer" together with "Check prerequisites" you will hopefully understand the most important facts to consider. As well the next activity is important: "spceify selection criterias for Worklist"; in subsection´"Customer Exits" a number of available Exits are listed which you can use if needed (i belive we have thre exits there), Any of the can be used if you have teh need to. Some of them are relate dmore to "after work" activities in EHS than for the "real" work: Use BOM to get BOS done/Prepared; what you need is a "maintenance" and "data transfer" concept between the "BOM" and how you would like to generate the BOS..I am sorry to say: this is all"customer" specific implementation and I am not aware of ayn kind of "Best Practise" here.
Regarding your explanation:
From my understanding, BOMBOS transfer will first generate the compositions of the BOM materials, then it will generate the Bill of substances.
I try it different:. You have one BOM; this BOM does have one "header material" and a number of items.
BOMBOS transfers/or generate (tro my knowledge) in most cases this: if REAL_SUB of Header material is not there it generated it,. If REAL_SUB per item is not there it generated that. And at the end the "Header" REAL_SUb will get the "itemn" Real_Sub as part of the composition.
BOMBOS tarnsfer is not discussed often in thie FORUM. Generally the SAP help is not"bad".
Check: Bill of Material Transfer - Product Safety (EHS-SAF) - SAP Library
and subsequent chapters. Transferring Bills of Material Manually - Product Safety (EHS-SAF) - SAP Library
C.B.