Good Morning!
Huarlem, I implemented with your suggestion. What is not happening, which may not have been clearer in my difficulty, is that the tree does not keep, if it was once collapsed or expanded.
I can do this using the node ID when building the tree and set it to the "isOpen" property. If the ID is the same as the one selected, it sets the setting I want.
Wouldn't there be a way to get the (+) or (-) element? Thus, it would not be necessary for me to click on any node to know which node will be collapsed or expanded.
As the attached image follows.
Thanks