diff --git a/comfy_api/latest/_io.py b/comfy_api/latest/_io.py
index d5bf711a3..26c1add7a 100644
--- a/comfy_api/latest/_io.py
+++ b/comfy_api/latest/_io.py
@@ -2057,11 +2057,22 @@ class Schema:
                 nested_inputs.extend(input.get_all())
         input_ids = [i.id for i in nested_inputs]
         input_set = set(input_ids)
-        combo_inputs = {i.id: i for i in self.inputs if isinstance(i, DynamicCombo.Input)}
-        slot_inputs = {i.id: i for i in self.inputs if isinstance(i, DynamicSlot.Input)}
-        # selector lookup covers both static (nested) inputs and DynamicCombo/Slot
-        # top-level inputs, since DynamicInput instances aren't included in nested_inputs.
-        all_selectable_ids = input_set | set(combo_inputs) | set(slot_inputs)
+        # Walk DynamicCombo / DynamicSlot options so a DynamicOutputs selector can
+        # target a nested dynamic input by dotted path (e.g. "outer.inner_slot").
+        # Other DynamicInput kinds (e.g. Autogrow) are skipped — their nested ids
+        # only exist at prompt time and aren't statically addressable.
+        selector_targets: dict[str, Input] = {}
+        def _walk(inputs: list[Input], prefix: str | None) -> None:
+            for inp in inputs:
+                dotted = inp.id if prefix is None else f"{prefix}.{inp.id}"
+                selector_targets[dotted] = inp
+                if isinstance(inp, (DynamicCombo.Input, DynamicSlot.Input)):
+                    for opt in inp.options:
+                        _walk(opt.inputs, dotted)
+        _walk(self.inputs, None)
+        combo_inputs = {sid: inp for sid, inp in selector_targets.items() if isinstance(inp, DynamicCombo.Input)}
+        slot_inputs = {sid: inp for sid, inp in selector_targets.items() if isinstance(inp, DynamicSlot.Input)}
+        all_selectable_ids = input_set | set(selector_targets)
 
         # ``output_ids`` covers every id that may ever appear in a finalized
         # output list — static outputs + every option's outputs across every
diff --git a/tests-unit/comfy_api_test/test_dynamic_outputs.py b/tests-unit/comfy_api_test/test_dynamic_outputs.py
index f15e442cb..60d6a20ef 100644
--- a/tests-unit/comfy_api_test/test_dynamic_outputs.py
+++ b/tests-unit/comfy_api_test/test_dynamic_outputs.py
@@ -440,3 +440,98 @@ def test_v1_info_emits_byslot_entry():
     assert entry["selector"] == "slot"
     whens = [opt["when"] for opt in entry["options"]]
     assert whens == [["IMAGE"], ["LATENT"], None]
+
+
+# ---------------------------------------------------------------------------
+# Nested dynamic selectors (selector reaches into a DynamicCombo / DynamicSlot
+# option's nested inputs via a dotted path).
+# ---------------------------------------------------------------------------
+
+def test_schema_accepts_byslot_selector_into_nested_dynamic_slot():
+    """A BySlot selector may target a DynamicSlot nested inside a DynamicCombo option."""
+    class Nested(io.ComfyNode):
+        @classmethod
+        def define_schema(cls):
+            return io.Schema(
+                node_id="NestedBySlot",
+                inputs=[
+                    io.DynamicCombo.Input("outer", options=[
+                        io.DynamicCombo.Option(key="a", inputs=[
+                            io.DynamicSlot.Input("inner_slot", options=[
+                                io.DynamicSlot.Option(when=io.Image),
+                                io.DynamicSlot.Option(when=None),
+                            ]),
+                        ]),
+                    ]),
+                ],
+                outputs=[io.DynamicOutputs.BySlot(id="r", selector="outer.inner_slot", options=[
+                    io.DynamicOutputs.SlotOption(when=io.Image, outputs=[io.Image.Output("img")]),
+                    io.DynamicOutputs.SlotOption(when=None, outputs=[]),
+                ])],
+            )
+
+        @classmethod
+        def execute(cls, **kwargs):
+            return io.NodeOutput.from_named({})
+
+    # Must not raise — selector resolves to the nested DynamicSlot via dotted path.
+    Nested.GET_SCHEMA()
+
+
+def test_schema_accepts_bykey_selector_into_nested_dynamic_combo():
+    """A ByKey selector may target a DynamicCombo nested inside another DynamicCombo option."""
+    class Nested(io.ComfyNode):
+        @classmethod
+        def define_schema(cls):
+            return io.Schema(
+                node_id="NestedByKey",
+                inputs=[
+                    io.DynamicCombo.Input("outer", options=[
+                        io.DynamicCombo.Option(key="branch", inputs=[
+                            io.DynamicCombo.Input("inner", options=[
+                                io.DynamicCombo.Option(key="x", inputs=[]),
+                                io.DynamicCombo.Option(key="y", inputs=[]),
+                            ]),
+                        ]),
+                    ]),
+                ],
+                outputs=[io.DynamicOutputs.ByKey(id="r", selector="outer.inner", options=[
+                    io.DynamicOutputs.Option(key="x", outputs=[io.Int.Output("ix")]),
+                    io.DynamicOutputs.Option(key="y", outputs=[io.String.Output("iy")]),
+                ])],
+            )
+
+        @classmethod
+        def execute(cls, **kwargs):
+            return io.NodeOutput.from_named({})
+
+    Nested.GET_SCHEMA()
+
+
+def test_schema_rejects_byslot_nested_when_type_not_on_target_slot():
+    """The when-type alignment check follows the dotted selector into the nested slot."""
+    class BadNested(io.ComfyNode):
+        @classmethod
+        def define_schema(cls):
+            return io.Schema(
+                node_id="BadNested",
+                inputs=[
+                    io.DynamicCombo.Input("outer", options=[
+                        io.DynamicCombo.Option(key="a", inputs=[
+                            io.DynamicSlot.Input("inner_slot", options=[
+                                io.DynamicSlot.Option(when=io.Image),
+                            ]),
+                        ]),
+                    ]),
+                ],
+                outputs=[io.DynamicOutputs.BySlot(id="r", selector="outer.inner_slot", options=[
+                    io.DynamicOutputs.SlotOption(when=io.Audio, outputs=[io.Audio.Output("x")]),
+                ])],
+            )
+
+        @classmethod
+        def execute(cls, **kwargs):
+            return io.NodeOutput.from_named({})
+
+    with pytest.raises(ValueError, match=r"type\(s\) \['AUDIO'\] are not accepted"):
+        BadNested.GET_SCHEMA()