From a62428bc2c252a6eef79a672f489f2d8b32edf54 Mon Sep 17 00:00:00 2001
From: Ihor Yeromin <yeryomin.igor@gmail.com>
Date: Mon, 14 Jul 2025 16:39:39 +0200
Subject: [PATCH] feat(transformations): filter selection

---
 .../grafana-data/src/transformations/transformers/groupBy.ts   | 2 +-
 .../features/transformers/editors/GroupByTransformerEditor.tsx | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/grafana-data/src/transformations/transformers/groupBy.ts b/packages/grafana-data/src/transformations/transformers/groupBy.ts
index 8048c17faa7..f6eb212a138 100644
--- a/packages/grafana-data/src/transformations/transformers/groupBy.ts
+++ b/packages/grafana-data/src/transformations/transformers/groupBy.ts
@@ -10,7 +10,7 @@ import { FieldMatcherID } from '../matchers/ids';
 import { DataTransformerID } from './ids';
 import { findMaxFields } from './utils';
 
-const MINIMUM_FIELDS_REQUIRED = 2;
+const MINIMUM_FIELDS_REQUIRED = 1;
 
 export enum GroupByOperationID {
   aggregate = 'aggregate',
diff --git a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
index be898922aa2..ebd2a55661d 100644
--- a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
+++ b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
@@ -132,6 +132,9 @@ const GroupByFieldConfiguration = ({ fieldName, config, onConfigChange }: FieldP
             onChange={(stats) => {
               onConfigChange({ ...config, aggregations: stats as ReducerID[] });
             }}
+            filterOptions={(option) =>
+              config?.operation === GroupByOperationID.groupBy ? option.id === ReducerID.count : true
+            }
           />
         )}
       </Stack>