as your project grows, you keep opening and closing different jdeveloper applications. if you are not using jdeveloper’s default application folder path, say c:/JDeveloper/mywork, you should be trying to navigate in open application diagram to your own folder.

to make life easier, you can change default folder for open application dialog of jdeveloper as in following screenshot. you need to change path attribute of workDirectory tag in %appdata%\JDeveloper\_related_jdev_system_folder_\o.jdeveloper\applications.xml.