Usually referred to as "fractional" roles - often used for senior advisors and executive board level posts, and for CxO roles that aren't central to the business (eg. CFO for non-finance companies, CTO/CIO for non-tech companies).

I wouldn't expect to see it for sales so much, as it would mess with the incentive structure and you kind of want your salesfolk to be "all in". Same goes for CEO or COO - they might have a small portfolio of non-exec board memberships (or similar) on the side, but it's hard to do a good job if your primary focus is split between multiple distinct businesses.