'Choose file' sidebar options disappeared When you go to a website with a file uploader you click on a choose file and a pop up window appears with a sidebar similar to what you have in your standard finder window, however recently all of the options like Documents, Downloads, Pictures etc are no longer present, now I can only see ak52-macbook and remote disk. In standard finder windows I have all my standard folders plus custom ones that I added. I made sure in finder preferences that all of them are displayed.

I could not find anything in the finder or chrome browser preferences regarding this so here is my question, how do I display all of those folder in the pick file to upload pop up sidebar?
The kind of items in your case hidden are named Favourites. To show them, go to a site where you can upload a file (e.g. https://encodable.com/uploaddemo/) and then click on "Choose File", like you said. When you are prompted to upload something, just hover your cursor on the Favourites line, located on the top of the sidebar. A "Show" button will be shown (no irony, at all). Click it and all of the items will re-appear. Done!

If you have any more issues with this, feel free to comment.