I think the key skills are transferrable definitely. The core competency of a CFO is partnering, both internally with senior management and board members and externally with relationships with banks, auditors and other key stakeholders. Finance skills are important obviously, but soft skills more so as you generally have a team under you that can handle the detail and operational aspects of finance.
The management skill of leading a team is also key and this will be transferrable from one to the other.
In terms of what else would be needed, it is difficult to say without knowing your day to day role. Job titles are helpful but every company uses them differently so what one business partner or CFO does is not necessarily the same as another.
The main skill to learn I think would be to move from a tactical oriented mindset to a strategic one who looks at the ‘bigger’ picture and the company and enivronment as a whole rather than just the section of it with whom you are partnering. Demonstrating awareness of the marco and micro environments the business operates in, its challenges and opportunities would be key and offering a longer term strategic outlook and opinion as well.
Regulatory knowledge and compliance would also be important skills to know – risk management and required tools, corporate governance for your sector and a wider knowledge of all finance areas, as usually you will have oversight of all of these, which a business partnering role may not touch on. These could include treasury and compliance for example (listed or US companies require specific knowledge for example). Again, you would have team members usually with good detailed knowlege on these subjects but an understanding and overview at least is required to be able to coach and guide your team and challenge findings where necessary.
By no means a comprehensive response but hope it helps.