diff --git a/python/ray/rllib/utils/__init__.py b/python/ray/rllib/utils/__init__.py
index a738e7419..c25cefeb4 100644
--- a/python/ray/rllib/utils/__init__.py
+++ b/python/ray/rllib/utils/__init__.py
@@ -1,43 +1,10 @@
-import copy
-
 from ray.rllib.utils.filter_manager import FilterManager
 from ray.rllib.utils.filter import Filter
 from ray.rllib.utils.policy_client import PolicyClient
 from ray.rllib.utils.policy_server import PolicyServer
+from ray.tune.util import merge_dicts, deep_update
 
-__all__ = ["Filter", "FilterManager", "PolicyClient", "PolicyServer"]
-
-
-def merge_dicts(d1, d2):
-    """Returns a new dict that is d1 and d2 deep merged."""
-    merged = copy.deepcopy(d1)
-    deep_update(merged, d2, True, [])
-    return merged
-
-
-def deep_update(original, new_dict, new_keys_allowed, whitelist):
-    """Updates original dict with values from new_dict recursively.
-    If new key is introduced in new_dict, then if new_keys_allowed is not
-    True, an error will be thrown. Further, for sub-dicts, if the key is
-    in the whitelist, then new subkeys can be introduced.
-
-    Args:
-        original (dict): Dictionary with default values.
-        new_dict (dict): Dictionary with values to be updated
-        new_keys_allowed (bool): Whether new keys are allowed.
-        whitelist (list): List of keys that correspond to dict values
-            where new subkeys can be introduced. This is only at
-            the top level.
-    """
-    for k, value in new_dict.items():
-        if k not in original:
-            if not new_keys_allowed:
-                raise Exception("Unknown config parameter `{}` ".format(k))
-        if type(original.get(k)) is dict:
-            if k in whitelist:
-                deep_update(original[k], value, True, [])
-            else:
-                deep_update(original[k], value, new_keys_allowed, [])
-        else:
-            original[k] = value
-    return original
+__all__ = [
+    "Filter", "FilterManager", "PolicyClient", "PolicyServer", "merge_dicts",
+    "deep_update"
+]
diff --git a/python/ray/tune/examples/hyperopt_example.py b/python/ray/tune/examples/hyperopt_example.py
index 2898bf26d..d70d16b94 100644
--- a/python/ray/tune/examples/hyperopt_example.py
+++ b/python/ray/tune/examples/hyperopt_example.py
@@ -17,7 +17,7 @@ def easy_objective(config, reporter):
     time.sleep(0.2)
     assert type(config["activation"]) == str, \
         "Config is incorrect: {}".format(type(config["activation"]))
-    for i in range(100):
+    for i in range(config["iterations"]):
         reporter(
             timesteps_total=i,
             neg_mean_loss=-(config["height"] - 14)**2 +
@@ -47,6 +47,9 @@ if __name__ == '__main__':
         "my_exp": {
             "run": "exp",
             "num_samples": 10 if args.smoke_test else 1000,
+            "config": {
+                "iterations": 100,
+            },
             "stop": {
                 "timesteps_total": 100
             },
diff --git a/python/ray/tune/suggest/suggestion.py b/python/ray/tune/suggest/suggestion.py
index aa6cbe717..f6e7d532a 100644
--- a/python/ray/tune/suggest/suggestion.py
+++ b/python/ray/tune/suggest/suggestion.py
@@ -7,10 +7,11 @@ import copy
 
 from ray.tune.error import TuneError
 from ray.tune.trial import Trial
+from ray.tune.util import merge_dicts
 from ray.tune.experiment import convert_to_experiment_list
 from ray.tune.config_parser import make_parser, create_trial_from_spec
 from ray.tune.suggest.search import SearchAlgorithm
-from ray.tune.suggest.variant_generator import format_vars
+from ray.tune.suggest.variant_generator import format_vars, resolve_nested_dict
 
 
 class SuggestionAlgorithm(SearchAlgorithm):
@@ -33,9 +34,6 @@ class SuggestionAlgorithm(SearchAlgorithm):
 
     def __init__(self):
         """Constructs a generator given experiment specifications.
-
-        Arguments:
-            experiments (Experiment | list | dict): Experiments to run.
         """
         self._parser = make_parser()
         self._trial_generator = []
@@ -91,10 +89,11 @@ class SuggestionAlgorithm(SearchAlgorithm):
                 else:
                     break
             spec = copy.deepcopy(experiment_spec)
-            spec["config"] = suggested_config
+            spec["config"] = merge_dicts(spec["config"], suggested_config)
+            flattened_config = resolve_nested_dict(spec["config"])
             self._counter += 1
             tag = "{0}_{1}".format(
-                str(self._counter), format_vars(spec["config"]))
+                str(self._counter), format_vars(flattened_config))
             yield create_trial_from_spec(
                 spec,
                 output_path,
diff --git a/python/ray/tune/suggest/variant_generator.py b/python/ray/tune/suggest/variant_generator.py
index c3ca83e0a..09729f988 100644
--- a/python/ray/tune/suggest/variant_generator.py
+++ b/python/ray/tune/suggest/variant_generator.py
@@ -93,6 +93,21 @@ _STANDARD_IMPORTS = {
 _MAX_RESOLUTION_PASSES = 20
 
 
+def resolve_nested_dict(nested_dict):
+    """Flattens a nested dict by joining keys into tuple of paths.
+
+    Can then be passed into `format_vars`.
+    """
+    res = {}
+    for k, v in nested_dict.items():
+        if isinstance(v, dict):
+            for k_, v_ in resolve_nested_dict(v).items():
+                res[(k, ) + k_] = v_
+        else:
+            res[(k, )] = v
+    return res
+
+
 def format_vars(resolved_vars):
     out = []
     for path, value in sorted(resolved_vars.items()):
diff --git a/python/ray/tune/test/trial_runner_test.py b/python/ray/tune/test/trial_runner_test.py
index 40b6575ce..141936b70 100644
--- a/python/ray/tune/test/trial_runner_test.py
+++ b/python/ray/tune/test/trial_runner_test.py
@@ -26,7 +26,8 @@ from ray.tune.trial_runner import TrialRunner
 from ray.tune.suggest import grid_search, BasicVariantGenerator
 from ray.tune.suggest.suggestion import (_MockSuggestionAlgorithm,
                                          SuggestionAlgorithm)
-from ray.tune.suggest.variant_generator import RecursiveDependencyError
+from ray.tune.suggest.variant_generator import (RecursiveDependencyError,
+                                                resolve_nested_dict)
 
 if sys.version_info >= (3, 3):
     from unittest.mock import patch
@@ -902,6 +903,20 @@ class VariantGeneratorTest(unittest.TestCase):
         self.assertEqual(trials[0].config, {"x": 100, "y": 1})
         self.assertEqual(trials[1].config, {"x": 200, "y": 1})
 
+    def test_resolve_dict(self):
+        config = {
+            "a": {
+                "b": 1,
+                "c": 2,
+            },
+            "b": {
+                "a": 3
+            }
+        }
+        resolved = resolve_nested_dict(config)
+        for k, v in [(("a", "b"), 1), (("a", "c"), 2), (("b", "a"), 3)]:
+            self.assertEqual(resolved.get(k), v)
+
     def testRecursiveDep(self):
         try:
             list(
@@ -1651,5 +1666,18 @@ class TrialRunnerTest(unittest.TestCase):
         self.assertRaises(TuneError, runner.step)
 
 
+class SearchAlgorithmTest(unittest.TestCase):
+    def testNestedSuggestion(self):
+        class TestSuggestion(SuggestionAlgorithm):
+            def _suggest(self, trial_id):
+                return {"a": {"b": {"c": {"d": 4, "e": 5}}}}
+
+        alg = TestSuggestion()
+        alg.add_configurations({"test": {"run": "__fake"}})
+        trial = alg.next_trials()[0]
+        self.assertTrue("e=5" in trial.experiment_tag)
+        self.assertTrue("d=4" in trial.experiment_tag)
+
+
 if __name__ == "__main__":
     unittest.main(verbosity=2)
diff --git a/python/ray/tune/util.py b/python/ray/tune/util.py
index 9c047fd80..5d2db2726 100644
--- a/python/ray/tune/util.py
+++ b/python/ray/tune/util.py
@@ -3,6 +3,7 @@ from __future__ import division
 from __future__ import print_function
 
 import base64
+import copy
 import numpy as np
 
 import ray
@@ -35,6 +36,41 @@ def get_pinned_object(pinned_id):
             ObjectID(base64.b64decode(pinned_id[len(PINNED_OBJECT_PREFIX):]))))
 
 
+def merge_dicts(d1, d2):
+    """Returns a new dict that is d1 and d2 deep merged."""
+    merged = copy.deepcopy(d1)
+    deep_update(merged, d2, True, [])
+    return merged
+
+
+def deep_update(original, new_dict, new_keys_allowed, whitelist):
+    """Updates original dict with values from new_dict recursively.
+    If new key is introduced in new_dict, then if new_keys_allowed is not
+    True, an error will be thrown. Further, for sub-dicts, if the key is
+    in the whitelist, then new subkeys can be introduced.
+
+    Args:
+        original (dict): Dictionary with default values.
+        new_dict (dict): Dictionary with values to be updated
+        new_keys_allowed (bool): Whether new keys are allowed.
+        whitelist (list): List of keys that correspond to dict values
+            where new subkeys can be introduced. This is only at
+            the top level.
+    """
+    for k, value in new_dict.items():
+        if k not in original:
+            if not new_keys_allowed:
+                raise Exception("Unknown config parameter `{}` ".format(k))
+        if type(original.get(k)) is dict:
+            if k in whitelist:
+                deep_update(original[k], value, True, [])
+            else:
+                deep_update(original[k], value, new_keys_allowed, [])
+        else:
+            original[k] = value
+    return original
+
+
 def _to_pinnable(obj):
     """Converts obj to a form that can be pinned in object store memory.