Toggle is a meta-operation which modifies the behaviour tree’s root/start node, so I think that it’s not really what you are after 🙂
Even though your desired behaviour can be achieved with some ways, I really like your suggested node to make it easier, kind of a Selector that will alter the order of it’s child nodes in some way.
What came to my mind is a Composite that uses it’s child nodes kind like a ‘Stack’, pushing and looping the indexes forward (or backward) after each execution, something like this (4 child nodes):
0,1,2,3
3,0,1,2
2,3,0,1
etc…
I am not sure if thats clear 🙂
So in effect if you have just 2 childs, it will alter between those 2 after each complete execution of the node.
I will give some more thought on that of course, but yes, nice idea 🙂