Creating Lower-Level TBOMs 
You can use lower-level TBOMs when you wish to select different paths consecutively with one transaction. Each affected object is then listed in the lower-level TBOMs. The higher-level TBOM comprises the sum of all objects. This means its own objects as well as those of the lower-level TBOMs.
You can add any number of lower-level TBOMs to a TBOM. Other levels are not possible. This means that lower-level TBOMs cannot contain further lower-level TBOMs.
The user parameter AGS_BPCA_TBOM_CHILDS has the value "X" for your user.
You have created a TBOM for a transaction. The selected TBOM is not blocked for processing by another user.
Open the attributes of the transaction whose TBOM you wish to extend.
Choose the TBOM tab.
Choose Create Lower-Level TBOM.
Choose whether you wish to create the lower-level TBOM as a dynamic, static, or dynamic and static TBOM (for more information about the creation types, see Creating TBOMs).
Save your entries.