This is the 1122nd most frequent Turkish word.
geçtiği
"Geçtiği" means "that/which/where [he/she/it] passes" or "passed" in English.
'Geçtiği' here indicates passing a test or a similar hurdle.
O, sınavdan geçtiği için çok mutluydu.
She was very happy because she passed the exam.
'Geçtiği' in this context refers to where an event (the movie) occurs.
Filmin geçtiği yer İstanbul'dur.
The place where the movie takes place is Istanbul.
'Geçtiği' is used here to refer to the passage or ending of an event (the rain).