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diff --git a/src/prompt_toolkit/completion/nested.py b/src/prompt_toolkit/completion/nested.py
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+++ b/src/prompt_toolkit/completion/nested.py
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+"""
+Nestedcompleter for completion of hierarchical data structures.
+"""
+from typing import Any, Dict, Iterable, Mapping, Optional, Set, Union
+
+from prompt_toolkit.completion import CompleteEvent, Completer, Completion
+from prompt_toolkit.completion.word_completer import WordCompleter
+from prompt_toolkit.document import Document
+
+__all__ = ["NestedCompleter"]
+
+# NestedDict = Mapping[str, Union['NestedDict', Set[str], None, Completer]]
+NestedDict = Mapping[str, Union[Any, Set[str], None, Completer]]
+
+
+class NestedCompleter(Completer):
+    """
+    Completer which wraps around several other completers, and calls any the
+    one that corresponds with the first word of the input.
+
+    By combining multiple `NestedCompleter` instances, we can achieve multiple
+    hierarchical levels of autocompletion. This is useful when `WordCompleter`
+    is not sufficient.
+
+    If you need multiple levels, check out the `from_nested_dict` classmethod.
+    """
+
+    def __init__(
+        self, options: Dict[str, Optional[Completer]], ignore_case: bool = True
+    ) -> None:
+
+        self.options = options
+        self.ignore_case = ignore_case
+
+    def __repr__(self) -> str:
+        return f"NestedCompleter({self.options!r}, ignore_case={self.ignore_case!r})"
+
+    @classmethod
+    def from_nested_dict(cls, data: NestedDict) -> "NestedCompleter":
+        """
+        Create a `NestedCompleter`, starting from a nested dictionary data
+        structure, like this:
+
+        .. code::
+
+            data = {
+                'show': {
+                    'version': None,
+                    'interfaces': None,
+                    'clock': None,
+                    'ip': {'interface': {'brief'}}
+                },
+                'exit': None
+                'enable': None
+            }
+
+        The value should be `None` if there is no further completion at some
+        point. If all values in the dictionary are None, it is also possible to
+        use a set instead.
+
+        Values in this data structure can be a completers as well.
+        """
+        options: Dict[str, Optional[Completer]] = {}
+        for key, value in data.items():
+            if isinstance(value, Completer):
+                options[key] = value
+            elif isinstance(value, dict):
+                options[key] = cls.from_nested_dict(value)
+            elif isinstance(value, set):
+                options[key] = cls.from_nested_dict({item: None for item in value})
+            else:
+                assert value is None
+                options[key] = None
+
+        return cls(options)
+
+    def get_completions(
+        self, document: Document, complete_event: CompleteEvent
+    ) -> Iterable[Completion]:
+        # Split document.
+        text = document.text_before_cursor.lstrip()
+        stripped_len = len(document.text_before_cursor) - len(text)
+
+        # If there is a space, check for the first term, and use a
+        # subcompleter.
+        if " " in text:
+            first_term = text.split()[0]
+            completer = self.options.get(first_term)
+
+            # If we have a sub completer, use this for the completions.
+            if completer is not None:
+                remaining_text = text[len(first_term) :].lstrip()
+                move_cursor = len(text) - len(remaining_text) + stripped_len
+
+                new_document = Document(
+                    remaining_text,
+                    cursor_position=document.cursor_position - move_cursor,
+                )
+
+                yield from completer.get_completions(new_document, complete_event)
+
+        # No space in the input: behave exactly like `WordCompleter`.
+        else:
+            completer = WordCompleter(
+                list(self.options.keys()), ignore_case=self.ignore_case
+            )
+            yield from completer.get_completions(document, complete_event)