I currently have 2 lookup list. one for The managers of that department that approve and other list has all the training courses and dates.
I have one main list where all the training is inputted. This list kicks off a sharepoint 2013 workflow (inside the workflow I use a task list to assign the task to a manager stage, then a finance stage and another stage to the original user.
I saw someone has posted a screenshot like the one below.
if I can use dffs with the workflow then great but I use the workflows now for the task approvals and to send email