I have two field values(a,b) in one field name(c). How can i show those two values(a,b) as two fields on Sankey visualization in a sequential way in two different nodes(one after another node)

[saicool]

I have two field values a, b, those are encapsulated in one field name called "c". I would like to show those two values on Sankey in a way of two different nodes or labels (i.e one after another). Please show me the right way to do that

Thanks