I can not find any info of the documentary BAMBOO THEATRE in HMDB.
Here are its imdb and douban page:
https://www.imdb.com/title/tt11080024/
https://movie.douban.com/subject/34847186/

Its director is CHEUK CHEUNG whose hkmdb page is here:

https://hkmdb.com/db/people/view.mhtml? ... ay_set=eng