How to change the view of all items of this type in a TreeView?

Question

WPF

Need to add a button to the right of each element of the desired type in the TreeView, found one answer, it works, but if you add a child element of the same type, it will look different. stackoverflow.com/questions/24569156/display-treev...
What it looks like now:

How do I do it:

How do I do it?