The short term roadmap can be viewed as a list of GitHub issues with Epic label. Typically Epics are created after an RFC is approved and merged.
The Hyperledger Fabric maintainers produce minor releases several times a year to deliver the release themes on the roadmap as they become ready, along with other smaller features, improvements, and fixes.
Longer term priorities that have not yet gone through RFC process are discussed in the community, for example Fabric Strategic Priorities - 2021 discussion.
See prior release notes for release history and content. Prior release documentation can be found in the documentation links.