diff --git a/tests/data/visits/exp_v6_347.json b/tests/data/visits/exp_v6_347.json
new file mode 100644
index 00000000..1e317b68
--- /dev/null
+++ b/tests/data/visits/exp_v6_347.json
@@ -0,0 +1,30 @@
+{
+    "definition": "exposure",
+    "record": {
+      "instrument": "DummyCam",
+      "id": 2022040500347,
+      "physical_filter": "dummy_u",
+      "obs_id": "AT_O_20220405_000347",
+      "exposure_time": 30.0,
+      "dark_time": 30.6038341522217,
+      "observation_type": "science",
+      "observation_reason": "object",
+      "day_obs": 20220405,
+      "seq_num": 347,
+      "seq_start": 347,
+      "seq_end": 347,
+      "group": "2022-04-06T02:56:53.255",
+      "target_name": "LATISS_E6A_00000027",
+      "science_program": "LATISS_E6A",
+      "tracking_ra": 221.548879575131,
+      "tracking_dec": -44.9667044639895,
+      "sky_angle": 358.536486388154,
+      "azimuth": 125.098359365453,
+      "zenith_angle": 44.1117566243774,
+      "has_simulated": false,
+      "timespan": [
+        1649213928006500400,
+        1649213958233000000
+      ]
+    }
+  }
diff --git a/tests/data/visits/exp_v6_348.json b/tests/data/visits/exp_v6_348.json
new file mode 100644
index 00000000..efdaea06
--- /dev/null
+++ b/tests/data/visits/exp_v6_348.json
@@ -0,0 +1,30 @@
+{
+    "definition": "exposure",
+    "record": {
+      "instrument": "DummyCam",
+      "id": 2022040500348,
+      "physical_filter": "dummy_u",
+      "obs_id": "AT_O_20220405_000348",
+      "exposure_time": 30.0,
+      "dark_time": 30.3176279067993,
+      "observation_type": "science",
+      "observation_reason": "object",
+      "day_obs": 20220405,
+      "seq_num": 348,
+      "seq_start": 348,
+      "seq_end": 349,
+      "group": "2022-04-06T02:58:07.181",
+      "target_name": "LATISS_E6A_00000040",
+      "science_program": "LATISS_E6A",
+      "tracking_ra": 222.00924897194,
+      "tracking_dec": -45.0610184451745,
+      "sky_angle": 358.485103614766,
+      "azimuth": 125.230189044465,
+      "zenith_angle": 44.3171011821396,
+      "has_simulated": false,
+      "timespan": [
+        1649213969056954600,
+        1649213999288000000
+      ]
+    }
+  }
diff --git a/tests/data/visits/exp_v6_349.json b/tests/data/visits/exp_v6_349.json
new file mode 100644
index 00000000..8c6aa810
--- /dev/null
+++ b/tests/data/visits/exp_v6_349.json
@@ -0,0 +1,30 @@
+{
+    "definition": "exposure",
+    "record": {
+      "instrument": "DummyCam",
+      "id": 2022040500349,
+      "physical_filter": "dummy_u",
+      "obs_id": "AT_O_20220405_000349",
+      "exposure_time": 30.0,
+      "dark_time": 30.2387452125549,
+      "observation_type": "science",
+      "observation_reason": "object",
+      "day_obs": 20220405,
+      "seq_num": 349,
+      "seq_start": 348,
+      "seq_end": 349,
+      "group": "2022-04-06T02:58:07.181",
+      "target_name": "LATISS_E6A_00000040",
+      "science_program": "LATISS_E6A",
+      "tracking_ra": 222.009071979566,
+      "tracking_dec": -45.060372917262,
+      "sky_angle": 358.484761155294,
+      "azimuth": 125.230292756547,
+      "zenith_angle": 44.2227120117313,
+      "has_simulated": false,
+      "timespan": [
+        1649214001607843600,
+        1649214031842000000
+      ]
+    }
+  }
diff --git a/tests/test_defineVisits.py b/tests/test_defineVisits.py
index 7050f19d..f0e13a40 100644
--- a/tests/test_defineVisits.py
+++ b/tests/test_defineVisits.py
@@ -53,10 +53,16 @@ def setUp(self):
         # Need to register the instrument.
         DummyCam().register(self.butler.registry)
 
+        # Choose serializations based on universe.
+        if "group" in self.butler.dimensions["exposure"].implied:
+            v = "_v6"
+        else:
+            v = ""
+
         # Read the exposure records.
         self.records: dict[int, DimensionRecord] = {}
         for i in (347, 348, 349):
-            with open(os.path.join(DATADIR, f"exp_{i}.json")) as fh:
+            with open(os.path.join(DATADIR, f"exp{v}_{i}.json")) as fh:
                 simple = SerializedDimensionRecord.model_validate_json(fh.read())
             self.records[i] = DimensionRecord.from_simple(simple, registry=self.butler.registry)
 
@@ -92,7 +98,18 @@ def define_visits(
         self, exposures: list[DimensionRecord | list[DimensionRecord]], incremental: bool
     ) -> None:
         for records in exposures:
-            self.butler.registry.insertDimensionData("exposure", *ensure_iterable(records))
+            records = list(ensure_iterable(records))
+            if "group" in self.butler.dimensions["exposure"].implied:
+                # This is a group + day_obs universe.
+                for rec in records:
+                    self.butler.registry.syncDimensionData(
+                        "group", dict(instrument=rec.instrument, name=rec.group)
+                    )
+                    self.butler.registry.syncDimensionData(
+                        "day_obs", dict(instrument=rec.instrument, id=rec.day_obs)
+                    )
+
+            self.butler.registry.insertDimensionData("exposure", *records)
             # Include all records so far in definition.
             dataIds = list(self.butler.registry.queryDataIds("exposure", instrument="DummyCam"))
             self.task.run(dataIds, incremental=incremental)
@@ -116,6 +133,17 @@ def test_incremental_cumulative_reverse(self):
         self.assertVisits()
 
     def define_visits_incrementally(self, exposure: DimensionRecord) -> None:
+        if "group" in self.butler.dimensions["exposure"].implied:
+            self.butler.registry.syncDimensionData(
+                "group", dict(instrument=exposure.instrument, name=exposure.group)
+            )
+            self.butler.registry.syncDimensionData(
+                "day_obs",
+                dict(
+                    instrument=exposure.instrument,
+                    id=exposure.day_obs,
+                ),
+            )
         self.butler.registry.insertDimensionData("exposure", exposure)
         dataIds = [
             DataCoordinate.standardize(