Thanks for your replies!
Only used families to spawn a random enemy and did not remember you can use them for actions.
I added a family instance var and set the 2 array IDs to BL3 and BL2.
I tried this and it seems to work fine. :)
+ System: On start of layout
-> Array: Set value at 0 to "BL3"
-> Array2: Set value at 0 to "BL2"
----+ System: Pick Family1 by evaluating Family1.ID="BL2"
-----> Text: Set text to Family1.At(0)
When I change the pick ID it shows a different value.