In Drupal 7, I would like to set up a rule that sends an email to all users in an ORGANIC GROUPS Role, based on an action. I know how to get the action, I know how to do the loop, I know how to send the email.
I cannot, for the life of me, figure out how to get a list of group members with group role "X".
PS - I've reviewed this link: http://www.sthlmconnection.se/en/blog/rules-based-notifications-organic-groups , and it's for D6.
I've submitted a patch to a similar issue for OG https://drupal.org/node/1859698#comment-8719475 which should allow you to do this in Rules without the need for a custom module or needing to know the role id.
Once you apply the patch, you can use the "Get group members from group audience" action, and now filter by the "Membership States" and "Group Roles". Then add a loop to go through the list and use the "Send mail" action to send an email to each member.