I could set up a role for a limited user (example name:)”test”, which just can create posts, attache media to it and give it to revision to the admin of the mother instance, which then checks the post and publish or deletes it.
This works fine when I log in at (example url) mother-instances.de/wp-admin with this user.
What I need next is that this role works for the user “test”, which is related to a certain blog/child instance.
When (example url) child-instances.de/wp-admin is such one, here the settings of the role are not given.
I suppose from your message, that you use WordPress multisite, and “mother instance” is a main blog, but “child instances” are subsites.
You should network activate User Role Editor.
Then after configuring ‘test’ role and ‘test’ user at the main blog, you may go to the “Network Admin->Users->User Role Editor” and click “Update Network” to replicate ‘test’ role to all subsites of this WordPress multisite installation.
Go to “Network Admin->Users”, select ‘test’ user and click ‘Capabilities’ link under his row. Then click “Update Network” button. This will add ‘test’ user with his current permissions (e.g. ‘test’ role assigned) to all subsites.
By default post created at WordPress multisite subsite A are available at the subsite A posts list only.
I may just suppose that you use some plugin or theme that allows to admin of the main site to see the posts from all subsites at one place, do you? It’s difficult to imagine something about logic of the unknown product.