unable user variable sets in flow designer

[venkatrajesh]

i am trying multiple ways to use the variable sets in flow designer  but not working

[venkatrajesh]

 have a two variable sets in catalog item. named Beforelive and Afterlive. in both variable sets L1 ,L2,L3 fields which are of type list collector

Now i need to create a catalog task for each value in L1 ,L2 and L3  and assigned to that particular group(value in L1,L2, L3).