Как отличить каталог только для файлов определенного типа?

У меня вопрос по команде diff if I want a recursive directory diff but only for a specific file type, how to do that?

I tried using the exclude option but can only use one pattern only:

$ diff /destination/dir/1 /destination/dir/2 -r -x *.xml

with the command I can only exclude xml file type, even though there are files in the folder image type (png, gif, jpg), txt, php, etc

how to diff only certain file types.