On the FOLIO Snapshot environment (https://folio-snapshot.dev.folio.org), there are a number of pre-configured "role-based" permission sets that you can use to explore different kinds of FOLIO functionality.
A list of available roles can be found in snapshot under Settings → Users → Permission Sets:
The actual assigned permissions can be found in Github here: https://github.com/folio-org/folio-tools/tree/master/add-users/psets
If you want to try one of these permission sets, the username / password is the name of the set, for example, if you want to try circ-staff, type username circ-staff and password circ-staff to log in.