I am not seeing the same thing as you.
When i go to environments, Under Access, i click on User then See All (as per your first picture) .
Here i am shown a list of users, but i dont see no option to export.
All i see is Add Users, Refresh, Manage Users in Dynamics 365.
If i click on Manager Users in Dynamics 365 i see a view called Enabled Users which consists of users who i dont think have access to the environment. There are other system views too
All i need is a view to show me everyone who has access to the environment and what security role they have