First search for assembly in AWC then click on the content tab on the left side you should see child parts listed.
attaching screen for reference.
Thanks for your reply. I tried the steps you mentioned, but still cannot see structure. Are there any additional configurations I need to do? I have installed Active content but still cannot see any structure.
Select a revision of your pipe (in print screen we can see A or B).
On the revision item you should see the Content tab if your pipe has any BoM underneath.