Is there a way to find out the distribution channels used for a particular blog post?

Of course.

Simply copy some paragraphs from the blog post and paste into Google and you’ll find some social networks where this post appeared.

Don’t copy the title, though, because the author may use different titles for different distribution channels.

Bear in mind that the author can choose to distribute a particular post weeks or months or years later so you may not find it on the social networks right away.

​Hope this helps.