In brief:
1) All stakeholders can submit an initiative to the MFF. This is done through a Benefit hypothesis (the format of which has yet to be published)
2) If the MFF adopts the topic on the basis of the Benefit hypothesis (according to the respectively decision types and voting ratios), facilitates the BAS in the elaboration of the Lean Business Case (LBC). The LBC contains, among other things, a solution direction, a proposal for the minimum composition of the working group, and all information to topic to prioritize.
3) The MFF approves the LBC, and approves the amended, prioritized portfolio.
4) The Topic Manager and his working group are responsible for the full realization of the topic. It follows the principles of SAFe/Agile from initiation at the MFF to with the realization.
See here for an extensive presentation that explains the new way of working. Name of document: Working method Bureau Appointments System.