Hello @Ankur A3,
I have an on reset trigger that adds objects to a group if the object fit a certain super class and that are not already in a group.
Array tree= model.subnodes.toArray();
for (int i=2; i<= tree.length; i++){
if(tree.find(">superclasses").subnodes[1].name == "FixedResource" && Group("Group1").indexOf(tree.as(Object)) == 0){
Group("Group1").addMember(tree);
}
}
If you were to open the Model Tree you will see that all objects are listed in the tree and I just go through that list of objects.
If you were to investigate on of those nodes you would notice that there is a subnode called superclasses that I am using to identify what items should be added. You will need to look at your custom objects and see if there is a unique class or superclass that will help you identify them and add them to the group.

Model Link