Tonkin Jasmine, 'Thiên lý' (Telosma cordata).
If you want more information about this flower, just search the plant's Latin name on Google:
The plant bears clusters of greenish yellow flowers along the vining stems during summer months. Individual blooms emerge successively over a period of weeks emitting a rich, heavy fragrance during the day and night. The flower buds are used in Southern Chinese cuisine, Vietnamese cuisine and Northern Thai cuisine, where they are stir-fried or boiled in broth. This is a tropical plant. USDA zones 10-12.