That's a great question. I'll be experimenting with something that may also help your needs. We would like to have private places with a group for only certain members to participate in. Our "workaround" might involve the creation of another private or secret group for this purpose. In the "main group", develop an HTML button that takes users to the private area. The downside is that many people will ultimately be denied access. Maybe you can create a separate group for your needs as well?
Keep in mind, this is bigger than just blogs. Any member can essentially contribute anything to a Group. So even if you lock down the blog, discussions, polls, documents and projects are still wide open for anyone to make a contribution. If you really need to control acess, spaces are the way to go.
Jesse is correct that permissions in a group apply to everyone. However, I would think about a couple of things. First, do you *really* need to "control access"? We get this requirement all the time, and often after a little digging, the issue is that people only want certain contributors--not everyone. It is extremely rare that someone "goes rogue" and posts official documentation or blogs if it is called out clearly that the purpose of the document or blog is for official communications. Think about wikipedia, open to everyone to edit, and consider the number of people who actually do it. Unless there is a real need for security or record retention, I would consider just leaving it open and labeling it appropriately.
Of course, it may take some time for folks in your organization to get comfortable with that mindset. In that case, a couple of options I can think of include:
- Using documents, on which you can control collaboration, even in a group. Just expand the Collaboration options at the end of the document and specify the people who can edit, comment, etc.
- Use a personal blog (probably the best option). Anyone can create a blog in their profile which is viewable by all, but editable only by them. You can then use the Pick Your Blog widget from the Catalyst plug-in to display this blog in a group. If the news should be coming from a department instead of a person, you could set up an account for that group. For example, you could have an Internal Communications profile and have the IC folks write to the personal blog.
There may be other options, including using spaces (of which I am not a fan), but having a separate group with different permissions will not work. There is no group permission level that is read-only, so any time you grant access to read the content in a group, you are also granting access to edit it.
Hope that helps.
There is an idea on creating a moderated blog in a Group:
Beyond that, unless I am misunderstanding the situation, I believe this is a feature that is not easily achievable as stated. Options definitely exist with Spaces, however, Groups currently are not able to do the functionality you describe as they are designed to enable equal access across the group when it comes to creating content to share with the "team".
That being said, I'm in favor of this feature, and have noted to see if I can figure something out to add to my Admin Essentials Plugin =)