diff --git a/model/insight/metric_data.go b/model/insight/metric_data.go
index f8a4e5fc..180488ad 100644
--- a/model/insight/metric_data.go
+++ b/model/insight/metric_data.go
@@ -70,11 +70,11 @@ type MetricItem struct {
 type MetricDataItem struct {
 	Timestamp interface{}  `json:"timestamp,omitempty"`
 	Value     interface{}    `json:"value"`
-	Group     string `json:"group,omitempty"`
+	Groups []string `json:"groups,omitempty"`
 }
 
 type MetricData struct {
-	Group     string `json:"group,omitempty"`
+	Groups []string `json:"groups,omitempty"`
 	Data map[string][]MetricDataItem
 }
 
diff --git a/plugin/api/insight/metadata.go b/plugin/api/insight/metadata.go
index c82d0841..187e7661 100644
--- a/plugin/api/insight/metadata.go
+++ b/plugin/api/insight/metadata.go
@@ -224,7 +224,7 @@ func getMetricData(metric *insight.Metric) (interface{}, error) {
 	}else {
 		for _, md := range metricData {
 			targetData := insight.MetricData{
-				Group: md.Group,
+				Groups: md.Groups,
 				Data:  map[string][]insight.MetricDataItem{},
 			}
 			expression, err := govaluate.NewEvaluableExpression(formula)
@@ -281,7 +281,7 @@ func getMetricData(metric *insight.Metric) (interface{}, error) {
 	for _, md := range targetMetricData {
 		for _, v := range md.Data {
 			for _, mitem := range v {
-				mitem.Group = md.Group
+				mitem.Groups = md.Groups
 				result = append(result, mitem)
 			}
 		}
diff --git a/plugin/api/insight/metric_util.go b/plugin/api/insight/metric_util.go
index ce973623..afc8ca93 100644
--- a/plugin/api/insight/metric_util.go
+++ b/plugin/api/insight/metric_util.go
@@ -196,21 +196,21 @@ func GenerateQuery(metric *insight.Metric) (interface{}, error) {
 func CollectMetricData(agg interface{}, timeBeforeGroup bool) []insight.MetricData {
 	metricData := []insight.MetricData{}
 	if timeBeforeGroup {
-		collectMetricDataOther(agg, "", &metricData, nil)
+		collectMetricDataOther(agg, nil, &metricData, nil)
 	} else {
-		collectMetricData(agg, "", &metricData)
+		collectMetricData(agg, nil, &metricData)
 	}
 	return metricData
 }
 
 // timeBeforeGroup => false
-func collectMetricData(agg interface{}, groupValues string, metricData *[]insight.MetricData) {
+func collectMetricData(agg interface{}, groupValues []string, metricData *[]insight.MetricData) {
 	if aggM, ok := agg.(map[string]interface{}); ok {
 		if timeBks, ok := aggM["time_buckets"].(map[string]interface{}); ok {
 			if bks, ok := timeBks["buckets"].([]interface{}); ok {
 				md := insight.MetricData{
 					Data:  map[string][]insight.MetricDataItem{},
-					Group: groupValues,
+					Groups: groupValues,
 				}
 				for _, bk := range bks {
 					if bkM, ok := bk.(map[string]interface{}); ok {
@@ -234,7 +234,7 @@ func collectMetricData(agg interface{}, groupValues string, metricData *[]insigh
 		} else {
 			md := insight.MetricData{
 				Data:  map[string][]insight.MetricDataItem{},
-				Group: groupValues,
+				Groups: groupValues,
 			}
 			for k, v := range aggM {
 				if k == "key" || k == "doc_count" {
@@ -245,10 +245,9 @@ func collectMetricData(agg interface{}, groupValues string, metricData *[]insigh
 						for _, bk := range bks {
 							if bkVal, ok := bk.(map[string]interface{}); ok {
 								var currentGroup = fmt.Sprintf("%v", bkVal["key"])
-								newGroupValues := currentGroup
-								if groupValues != "" {
-									newGroupValues = fmt.Sprintf("%s-%s", groupValues, currentGroup)
-								}
+								newGroupValues := make([]string, 0, len(groupValues)+1)
+								newGroupValues = append(newGroupValues, groupValues...)
+								newGroupValues = append(newGroupValues, currentGroup)
 								collectMetricData(bk, newGroupValues, metricData)
 							}
 						}
@@ -268,13 +267,13 @@ func collectMetricData(agg interface{}, groupValues string, metricData *[]insigh
 }
 
 // timeBeforeGroup => true
-func collectMetricDataOther(agg interface{}, groupValues string, metricData *[]insight.MetricData, timeKey interface{}) {
+func collectMetricDataOther(agg interface{}, groupValues []string, metricData *[]insight.MetricData, timeKey interface{}) {
 	if aggM, ok := agg.(map[string]interface{}); ok {
 		if timeBks, ok := aggM["time_buckets"].(map[string]interface{}); ok {
 			if bks, ok := timeBks["buckets"].([]interface{}); ok {
 				md := insight.MetricData{
 					Data:  map[string][]insight.MetricDataItem{},
-					Group: groupValues,
+					Groups: groupValues,
 				}
 				for _, bk := range bks {
 					if bkM, ok := bk.(map[string]interface{}); ok {
@@ -299,17 +298,16 @@ func collectMetricDataOther(agg interface{}, groupValues string, metricData *[]i
 		} else {
 			md := insight.MetricData{
 				Data:  map[string][]insight.MetricDataItem{},
-				Group: groupValues,
+				Groups: groupValues,
 			}
 
 			if bks, ok := aggM["buckets"].([]interface{}); ok {
 				for _, bk := range bks {
 					if bkVal, ok := bk.(map[string]interface{}); ok {
 						currentGroup := util.ToString(bkVal["key"])
-						newGroupValues := currentGroup
-						if groupValues != "" {
-							newGroupValues = fmt.Sprintf("%s-%s", groupValues, currentGroup)
-						}
+						newGroupValues := make([]string, 0, len(groupValues)+1)
+						newGroupValues = append(newGroupValues, groupValues...)
+						newGroupValues = append(newGroupValues, currentGroup)
 						collectMetricDataOther(bk, newGroupValues, metricData, timeKey)
 					}
 				}