The Last of Us Part I

You can complete collections through selecting chapters on any difficulty, and not necessarily on the one you completed the chapter on (there were problems with this in the original).
Go to the chapter selection, select the desired chapter on any difficulty, go into it and collect what you need, save, exit to the menu, load your last save from the original walkthrough (if you have already completed the game, then there will be something like a Backup autosave after passing, well, or load the last save from a normal walkthrough if you haven’t completed the game yet). This way, your findings will be included in your statistics without losing chapters.

Also in the settings there is a very useful function in the Interface menu. It's called "Tracking Finds" (last on the list). She checks off finds that you have already found in previous playthroughs (when you come to them). This will be useful if, for example, you missed only a couple of notes/icons from the beginning/middle of the chapter, but don’t remember which ones, and so as not to run to the end of the chapter and collect everything - it will help you understand when you found something that you didn’t find previously.