how to get only expanded node after open & close in CL_GUI_ALV_TREE?

Hi,

I have a tree structure using CL_GUI_ALV_TREE.

I would like to capture only the expanded nodes AFTER open and close operation.

If the user opens all the nodes and then closes them, I get all the nodes when using GET_EXPANDED_NODES.

I want to get only the expanded nodes that the user currently sees on the screen (so in open and close you will not get it as open).

whatever I tried doesn't work.

Do you have any idea how to do it?

Thanks,

Itay