diff --git a/crates/nu_plugin_polars/src/dataframe/command/aggregation/groupby.rs b/crates/nu_plugin_polars/src/dataframe/command/aggregation/groupby.rs
index 24372e47aa..8a98864655 100644
--- a/crates/nu_plugin_polars/src/dataframe/command/aggregation/groupby.rs
+++ b/crates/nu_plugin_polars/src/dataframe/command/aggregation/groupby.rs
@@ -39,9 +39,10 @@ impl PluginCommand for ToLazyGroupBy {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Group by and perform an aggregation",
-            example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
+        vec![
+            Example {
+                description: "Group by and perform an aggregation",
+                example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
     | polars into-lazy
     | polars group-by a
     | polars agg [
@@ -51,19 +52,45 @@ impl PluginCommand for ToLazyGroupBy {
      ]
     | polars collect
     | polars sort-by a"#,
-            result: Some(
-                NuDataFrame::from(
-                    df!(
-                        "a" => &[1i64, 2],
-                        "b_min" => &[2i64, 4],
-                        "b_max" => &[4i64, 6],
-                        "b_sum" => &[6i64, 10],
+                result: Some(
+                    NuDataFrame::from(
+                        df!(
+                            "a" => &[1i64, 2],
+                            "b_min" => &[2i64, 4],
+                            "b_max" => &[4i64, 6],
+                            "b_sum" => &[6i64, 10],
+                        )
+                        .expect("should not fail"),
                     )
-                    .expect("should not fail"),
-                )
-                .into_value(Span::test_data()),
-            ),
-        }]
+                    .into_value(Span::test_data()),
+                ),
+            },
+            Example {
+                description: "Group by an expression and perform an aggregation",
+                example: r#"[[a b]; [2025-04-01 1] [2025-04-02 2] [2025-04-03 3] [2025-04-04 4]]
+    | polars into-lazy
+    | polars group-by (polars col a | polars get-day | $in mod 2)
+    | polars agg [
+        (polars col b | polars min | polars as "b_min")
+        (polars col b | polars max | polars as "b_max")
+        (polars col b | polars sum | polars as "b_sum")
+     ]
+    | polars collect
+    | polars sort-by a"#,
+                result: Some(
+                    NuDataFrame::from(
+                        df!(
+                            "a" => &[0i64, 1],
+                            "b_min" => &[2i64, 1],
+                            "b_max" => &[4i64, 3],
+                            "b_sum" => &[6i64, 4],
+                        )
+                        .expect("should not fail"),
+                    )
+                    .into_value(Span::test_data()),
+                ),
+            },
+        ]
     }
 
     fn run(
@@ -79,11 +106,11 @@ impl PluginCommand for ToLazyGroupBy {
 
         if expressions
             .iter()
-            .any(|expr| !matches!(expr, Expr::Column(..)))
+            .any(|expr| matches!(expr, Expr::Agg(..) | Expr::Window { .. }))
         {
             let value: Value = call.req(0)?;
             Err(ShellError::IncompatibleParametersSingle {
-                msg: "Expected only Col expressions".into(),
+                msg: "Cannot group by an aggregation or window expression".into(),
                 span: value.span(),
             })?;
         }