Hi Brandon,
Yes, you can use the date/time functions in Fusion to do this. The 'Now' variable (available in date/time functions) behaves the same as the $$NOW wildcard in Workfront. Using this in combination with the 'add days' function should render the same results as a $$TODAY+3d Wildcard in Workfront. See screenshots below:
Variable configured with adddays function
Output produced
Best Regards,
Rich.