These roles should give enough permissions to backup and restore time-series collections including any secondary indexes defined on them.

The relevant privileges for the backup and restore roles are defined in the code here:

• backup - https://github.com/mongodb/mongo/blob/960f5deb14520af3076c9164fbf8b3cbcca0560f/src/mongo/db/auth/builtin_roles.cpp#L492
• restore - https://github.com/mongodb/mongo/blob/960f5deb14520af3076c9164fbf8b3cbcca0560f/src/mongo/db/auth/builtin_roles.cpp#L575

The time-series collection is considered a normal resource in the access control system. However, this does not apply to the buckets collection because it resides in the system.buckets namespace.

The AuthorizationSessionImpl::buildResourceSearchList function is responsible for checking whether an action is allowed to proceed on a resource.