A documentary stands for looking at life as it truly is, with facts in place of fiction. Watching one in a dream is read as the wish to understand a situation honestly.
Where in your waking life have you met something like this lately?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.