I am really confused by your answer...
suppose you have
1. FG1 Header Mat
Comp Mat SFG1 also Manufacturing Mat
2. SFG1 Header Mat
Comp Mat again SFG Manufacturing Mat
3. SFG Header Mat
Comp Mat must be a Raw Mat (procured)
Check that Raw Mat ..whether any price is there or not
There must be some level your BOM having a procured mat..what you are telling acn't be possible