I know this is an old post, but I think I have a solution (I had a similar experience earlier). It's a little complicated, but it definitely works!
- Install both [Feeds] (https://www.drupal.org/project/feeds) and [Feeds Tamper] (https://www.drupal.org/project/feeds_tamper)
- Create a content type to receive the feed entries.
*I'll call this new content type "Blog post"
- Add a text field to BOTH the new content type AND to your OG form.
*I'll call this field "Feed nickname"
- On your OG form, fill in the field with the appropriate feed nickname.
*I suggest making this a one-word nickname
- Under Structure>Feeds Importers>Edit>Node processor settings, select "Blog post" as the chosen bundle to receive the feed. Click save.
- Under Structure>Feeds Importers>Edit>Node processor mapping, add a new mapping with "Blank source" as the source and "Feed nickname" as the target. Click save.
- Under Structure>Feeds Importers>Tamper, scroll to the section "Blank source-> Feed nickname" and click "add plugin."
- Choose the plugin called "Set default value" and set the default value to your chosen feed nickname. Click save and make sure the plugin is enabled. Click save at the bottom of the tamper form.
- Add the feed importer as usual, under yoursite.org/import
Short explanation:
What this process does, essentially, is to assign all of the incoming feeds a default dummy value (in this case, the "feed nickname" you chose), and then match that value to the one you put in your content type. Having the same field and field value shared among the feed, the content type, and the OG links them together, and makes it possible for you to relate them in Views, etc.
Hope this helps!