diff --git a/cmd/joj3/conf/conf.go b/cmd/joj3/conf/conf.go
index 21b074a..ac1a90b 100644
--- a/cmd/joj3/conf/conf.go
+++ b/cmd/joj3/conf/conf.go
@@ -208,13 +208,6 @@ func MatchGroups(conf *Conf, conventionalCommit *ConventionalCommit) []string {
 	confStages = append(confStages, conf.Stages...)
 	confStages = append(confStages, conf.PostStages...)
 	for _, stage := range confStages {
-		if stage.Group != "" {
-			keyword := strings.ToLower(stage.Group)
-			if _, exists := seen[keyword]; !exists {
-				seen[keyword] = true
-				keywords = append(keywords, keyword)
-			}
-		}
 		if len(stage.Groups) > 0 {
 			for _, group := range stage.Groups {
 				keyword := strings.ToLower(group)
@@ -235,15 +228,12 @@ func MatchGroups(conf *Conf, conventionalCommit *ConventionalCommit) []string {
 	slog.Info("matched groups", "groups", groups)
 	if matchAllGroups {
 		for i := range conf.PreStages {
-			conf.PreStages[i].Group = ""
 			conf.PreStages[i].Groups = nil
 		}
 		for i := range conf.Stages {
-			conf.Stages[i].Group = ""
 			conf.Stages[i].Groups = nil
 		}
 		for i := range conf.PostStages {
-			conf.PostStages[i].Group = ""
 			conf.PostStages[i].Groups = nil
 		}
 	}
diff --git a/cmd/joj3/conf/model.go b/cmd/joj3/conf/model.go
index f7c8194..c7ac480 100644
--- a/cmd/joj3/conf/model.go
+++ b/cmd/joj3/conf/model.go
@@ -6,7 +6,6 @@ import (
 
 type ConfStage struct {
 	Name     string
-	Group    string // TODO: remove Group in the future
 	Groups   []string
 	Executor struct {
 		Name string
@@ -31,15 +30,6 @@ type Conf struct {
 	PreStages         []ConfStage
 	Stages            []ConfStage
 	PostStages        []ConfStage
-	// TODO: remove this nested struct
-	Stage struct {
-		SandboxExecServer string
-		SandboxToken      string
-		OutputPath        string
-		PreStages         []ConfStage
-		Stages            []ConfStage
-		PostStages        []ConfStage
-	}
 }
 
 type OptionalCmd struct {
diff --git a/cmd/joj3/main.go b/cmd/joj3/main.go
index 82edae5..a872ea7 100644
--- a/cmd/joj3/main.go
+++ b/cmd/joj3/main.go
@@ -78,31 +78,6 @@ func loadConf(confPath string) (*joj3Conf.Conf, error) {
 		slog.Error("parse conf", "error", err)
 		return nil, err
 	}
-	// TODO: remove this compatible code for nested struct
-	if conf.Stage.SandboxExecServer != "" {
-		conf.SandboxExecServer = conf.Stage.SandboxExecServer
-		conf.Stage.SandboxExecServer = ""
-	}
-	if conf.Stage.SandboxToken != "" {
-		conf.SandboxToken = conf.Stage.SandboxToken
-		conf.Stage.SandboxToken = ""
-	}
-	if conf.Stage.OutputPath != "" {
-		conf.OutputPath = conf.Stage.OutputPath
-		conf.Stage.OutputPath = ""
-	}
-	if len(conf.Stage.PreStages) > 0 {
-		conf.PreStages = conf.Stage.PreStages
-		conf.Stage.PreStages = nil
-	}
-	if len(conf.Stage.Stages) > 0 {
-		conf.Stages = conf.Stage.Stages
-		conf.Stage.Stages = nil
-	}
-	if len(conf.Stage.PostStages) > 0 {
-		conf.PostStages = conf.Stage.PostStages
-		conf.Stage.PostStages = nil
-	}
 	slog.Debug("conf loaded", "conf", conf, "joj3 version", Version)
 	return conf, nil
 }
diff --git a/cmd/joj3/stage.go b/cmd/joj3/stage.go
index 4c65710..12fc926 100644
--- a/cmd/joj3/stage.go
+++ b/cmd/joj3/stage.go
@@ -44,21 +44,13 @@ func generateStages(confStages []conf.ConfStage, groups []string) (
 	stages := []stage.Stage{}
 	existNames := map[string]bool{}
 	for i, s := range confStages {
-		if len(groups) == 0 && (len(s.Groups) != 0 || s.Group != "") {
+		if len(groups) == 0 && (len(s.Groups) != 0) {
 			continue
 		}
 		ok := false
-		if s.Group == "" && len(s.Groups) == 0 {
+		if len(s.Groups) == 0 {
 			ok = true
 		}
-		if !ok && s.Group != "" {
-			for _, group := range groups {
-				if strings.EqualFold(group, s.Group) {
-					ok = true
-					break
-				}
-			}
-		}
 		if !ok && len(s.Groups) > 0 {
 			for _, group := range groups {
 				for _, g := range s.Groups {
diff --git a/go.sum b/go.sum
index 43bfc33..549ae31 100644
--- a/go.sum
+++ b/go.sum
@@ -139,8 +139,6 @@ gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
 gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2 h1:2I6GHUeJ/4shcDpoUlLs/2WPnhg7yJwvXtqcMJt9liA=
 google.golang.org/genproto/googleapis/rpc v0.0.0-20251213004720-97cd9d5aeac2/go.mod h1:7i2o+ce6H/6BluujYR+kqX3GKH+dChPTQU19wjRPiGk=
-google.golang.org/grpc v1.79.1 h1:zGhSi45ODB9/p3VAawt9a+O/MULLl9dpizzNNpq7flY=
-google.golang.org/grpc v1.79.1/go.mod h1:KmT0Kjez+0dde/v2j9vzwoAScgEPx/Bw1CYChhHLrHQ=
 google.golang.org/grpc v1.79.3 h1:sybAEdRIEtvcD68Gx7dmnwjZKlyfuc61Dyo9pGXXkKE=
 google.golang.org/grpc v1.79.3/go.mod h1:KmT0Kjez+0dde/v2j9vzwoAScgEPx/Bw1CYChhHLrHQ=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=