Combining AND OR conditions in the discount wont work out properly.
Instead of using Presence of Specific Item in the cart, create a new cart column for Discountable. in the Add to cart buttons for items 1,2,3,4 set the Discountable column to 1 and for other items, set that column value to 0
then set the discount trigger as:
Session variable userLevel = 1
AND
number of items with a specific column value:
if the total number of items where "Discountable" has a value of "1" is ">" a value of "0"