Don't look at the embed tree. Look at the generated source. ie Right-Click on a procedure in the app tree and choose source.
the embed tree is sorted alphabetically, so 1,2 and 3 are just use for order. However to understand why there are 3 of them you should look at the source.
One should always look at the embedded code in context - reading the code around your embed code to see if what you're doing is in the right place, and in harmony with the code around it.
Incidentally, answer the question again, what is the location, by referring to the routine name in which it has been embedded.
Cheers
Bruce