Strategic Sourcing SelfCategorization Tree - Adding New Nodes and Sorting in Numeric Order

We are updating our SelfCategorization tree to add some additional nodes.

I am finding that I cannot add these "sibling nodes" in numeric order. It seems that any new "sibling node" is added to the bottom of the tree. Does anyone have experience with adding new nodes and sorting them so they are in numeric order?

Here are the steps I'm following:

1. Navigate to Create SelfCategorization Tree and Edit

2. Expand the Buy – Buy Categories

3.1 Either click on the category that will be directly above the category you are going to add and click on “Add Sibling Node” icon.

3.2 Or  select Buy Categories and click “Add Child Node” icon