diff --git a/pandas/core/groupby/grouper.py b/pandas/core/groupby/grouper.py
index e2224caad9e84..4bf2e8b90a0b0 100644
--- a/pandas/core/groupby/grouper.py
+++ b/pandas/core/groupby/grouper.py
@@ -1023,7 +1023,7 @@ def is_in_obj(gpr) -> bool:
             return False
 
     for gpr, level in zip(keys, levels):
-        if is_in_obj(gpr):  # df.groupby(df['name'])
+        if isinstance(obj, DataFrame) and is_in_obj(gpr):  # df.groupby(df['name'])
             in_axis = True
             exclusions.add(gpr.name)