Like most languages with modules.

Rust, Modula-2 and Ada are probably the only ones with module nesting.

Notably many languages in ML family have first class modules.

	▲	pjmlp 2 hours ago \| parent [-]
		Only Standard ML and OCaml, as far as I am aware. However this is a different kind of modules, with them being present on the type system, and manipulated via functors.