To open a file by its path, for example Example.groovy, do as follows:
1. Go to File --> Open File By Path... from the top menu.
2. Enter the path of the target file into the File URL field.
3. Click Open to show the Example.groovy file in the new file tab of the Content pane.
You can select View --> Get URL... from the top menu to obtain the file path.
The target file should be placed at the same domain as the IDE.