Missing Documentation for Vector Maps / Visualization Permissions

Versions (relevant - OpenSearch/Dashboard/Server OS/Browser): v 2.13.0

Describe the issue:
We are running the current v2.13 Opensearch Dashboards.
Currently facing the issue that only Admins with the all_access role can see the option to select the default or custom vector maps when creating a Region Map visualization.
There is no documentation on which cluster or index permission is needed to allow this possibility.
Any idea here?
Screenshot from 2024-05-06 10-19-40
See the different views in the attached screenshots

Configuration:

We do not want all users to have the all_access role on our cluster.
We would like to refine the permissions needed and restrict access via a custom role.
We have already tried granting full observability access permission but this did not change anything.

Relevant Logs or Screenshots: