Trigger an object blueprint function in level blueprint not working

I’m working on a small puzzle (hinoi tower) game in ue4.
I’ve made three blueprints for each tower, which determine how many elements the towers have.
Now, I need to have one blueprint where the three others can “meet up”, that is exchanging the picked value(smallest block from chosen tower). I have decided to use the Level Blueprint for that, and placed two functions (give and take) in all the tower blueprints. But somehow I can’t seem to “fire” the functions in the project blueprint (starting the function in the object blueprint works 100%). Here are the screens from the blueprints.
Would be glad for help.

https://dl.dropboxusercontent.com/u/69842270/screenshots/ue4proglems/project.JPG

https://dl.dropboxusercontent.com/u/69842270/screenshots/ue4proglems/function2.JPG

[biggur function][3]

ps. what I want to do with the function is to take the smallest element from it, and make the function return it in the tmp. As that goes the function will also replace the previous smallest value with 4 (which works as a empty space).