Two WP-Members login spaces in one WordPress install?

In the basic installation, the plugin does not differentiate in that way. However, it is not difficult to apply specific customizations to allow for handling user levels or groups depending on how it needs to be configured.

I generally look at “levels” like users in L1 can only view L1, but users in L2 can view L1 and L2, etc; whereas “groups” might be users in A can view A but not B, users in B can view B but not A.

The plugin can be customized to accommodate either of these scenarios and there are quite a few tutorials and code snippets on the plugin’s premium support site that discuss how to set things up. A couple examples are:
https://rocketgeek.com/filter-hooks/how-to-restrict-categories-to-a-defined-user-group/
https://rocketgeek.com/filter-hooks/restrict-content-by-user-level/