I want to make same functionality as tags working into a post. I want to add some custom file to be add as downloads, where i can add images/files/pdf from a URL, and it will saved as tags, we can delete the files names as tags do. I want to enter Filename in a text field, and url of file in another text field and add this information into selected fields. as per attached file.
Read more here:: How to add custom post widgets as tags into wordpress