Thanks for reaching out.
Here 22are the supported types of files you can attach to your content in the community. You can attach a file to your Post, Discussion, Article, and Question.
Currently, you cannot attach files to Answers, Comments, and replies. However, this is already resolved in our upcoming version. To learn about the timelines for V.2, please click here32.
There is no specific place that gathers all the shared files in the community or in a group. This is already on our product team's to-do list for the future.
I hope you found this answer helpful.