Refining the web application

There is an app written in java.
The application automates the test check. For this purpose, there are templates that can only be created, saved in xml format. And also download them.
You need to make the templates editable after they are saved in xml. Editing the templates themselves is possible, but manually, that is, directly edit the xml file. That is, you need the opportunity after saving the template in xml-format to re-impose this template on the picture. You need a kind of savepoint, from which you can then continue to create a template.