The film you saw last night was made based on a true story that happened many years ago .请问based on a true story 在句中作什么句子成分?

The film you saw last night was made based on a true story that happened many years ago .请问based on a true story 在句中作什么句子成分?
The film you saw last night was made based on a true story that happened many years ago .
请问based on a true story 在句中作什么句子成分?

The film you saw last night was made based on a true story that happened many years ago .请问based on a true story 在句中作什么句子成分?
状语
make a film based on a story
based on a story作状语修饰动词make

应该是状语

状语，修饰The film。

做宾语的。
主干是：the film was made based on atrue story。

which was based on , 状语

宾语