Just as twin strands make a rope stronger, is it smart career management to seek out twin-role jobs? One form of these is doing a combination of department & project roles, to build different kinds of skills and experiences.
Another form is to line-manage several functions. How can this be achieved if you have qualifications and work experience in one function only? Volunteer for short term tasks that give you that broader function exposure. Offer to take an oversight role of another support function in addition to your core one. In your next organisation, apply for a wider role.
As some organisations rationalise their senior management team, they’ll then want managers with wider functional experience. As people get promoted, more functions will inevitably come under their remit. Either way, the twin-strand form of business flexibility comes into its own.