What would you call the terminal leaf of a human organisation in layman term?

Question

Let's say you represent a human organisation with a tree data structure (organisation of a company, or for example for the USA you have the federal state then Texas inside it, then the county, then the township, etc.).

How would you say "This entity does not have anything inside it, it's a leaf or a terminal node in my tree structure" without using computer science term. If we were speaking about a genealogy tree it would be "This person did not have any child". Only I want a term that is applicable for an administrative entity, inside other administrative entities, not a person.

How is it possible to tell "The Escuadra de maniobra does not rule over any other spanish military entity" or "The civil township is one of the possible lowest level of administrative division in the USA"?

Answer 1

Perhaps, you could say that the administrative division is atomic.

Of or forming a single irreducible unit or component in a larger system

[ODO sense 1.2]

Answer 2

You're referring to someone/something at the bottom of the ladder (see also corporate ladder).

There are several similar idioms:

• At the bottom of the...

  • ...food chain
  • ...totem pole

In a word, an employee at that level is a grunt:

a person with little or no authority in some organization; UNDERLING, SUBORDINATE.
_{-Online Slang Dictionary}

Answer 3

nonsupervisory

Wiktionary:

Adjective nonsupervisory ‎(not comparable):

Not of a supervisory character; not engaged in supervision : a nonsupervisory worker

Adjective supervisory ‎(comparative more supervisory, superlative most supervisory):

Of, pertaining to, or in the capacity of a supervisor

Noun supervisor ‎(plural supervisors):

(management) A person with the official task of overseeing the work of a person or group, or of other operations and activities.