Navigate to Confluence administration > Microblog > Permissions.
Alternatively, click on the settings button in your Linchpin header, then click on the Microblog link. Then choose the Permissions tab.
As an administrator, you can choose which users can post or reply inside the Microblog.
Under Permission type you can select the user permissions needed to reply to microposts and to create new microposts.
To choose a permission type, click on the button with two arrows. This will open a drop-down menu.
You can choose between following options:
Only users with permission to add pages to a space will be able to create and reply to microposts. This is the default setting.
Only users with permission to add comments to a space will be able to create and reply to microposts.
Add blog posts
Only users with permission to add blog posts to a space will be able to create and reply to microposts.
The setting you choose here will apply to all spaces within your Confluence instance.
Furthermore, it doesn't matter if a permission is granted individually or if the user is part of a group with said permissions.
The readability and visibility fo the Microblog is managed by the read permission of spaces which contain the Microblog topics..
Microposts of a certain topic are only visible to people who have read permissions in spaces which contain the topics.
It does not matter where the Microblog is placed. The visibility is only dependent on the topics and the spaces which accommodate the topics.
Read how to configure topics for the Microblog.
Link to this page: https://seibert.biz/microblogpermissions