I have a requirement of hiding/unhiding few nodes from a tree alv based on some button click on the tool bar on the control. For this what I did is I utilised the change_node method of the class cl_gui_alv_tree. While Hiding the nodes I am passing 'X' in IS_NODE_LAYOUT-hidden and IS_NODE_LAYOUT-u_hidden and after that calling the method frontend_update. It is working perfectly fine, but while unhiding, I am passing blank spaces in these structures and then calling the frontend_update method but it is not working in that case. Could some let me know if I am missing something here or whether this can be done in any alternative ways?