diff --git a/server/events/yaml/raw/repo_cfg_test.go b/server/events/yaml/raw/repo_cfg_test.go
index 430b8c61b9..aa2deb8c95 100644
--- a/server/events/yaml/raw/repo_cfg_test.go
+++ b/server/events/yaml/raw/repo_cfg_test.go
@@ -144,7 +144,10 @@ workflows:
     policy_check:
       steps: []
     apply:
-     steps: []`,
+     steps: []
+allowed_regexp_prefixes:
+- dev/
+- staging/`,
 			exp: raw.RepoCfg{
 				Version:       Int(3),
 				Automerge:     Bool(true),
@@ -176,6 +179,7 @@ workflows:
 						},
 					},
 				},
+				AllowedRegexpPrefixes: []string{"dev/", "staging/"},
 			},
 		},
 	}
diff --git a/server/events/yaml/valid/repo_cfg_test.go b/server/events/yaml/valid/repo_cfg_test.go
new file mode 100644
index 0000000000..28cee4fc9f
--- /dev/null
+++ b/server/events/yaml/valid/repo_cfg_test.go
@@ -0,0 +1,175 @@
+package valid_test
+
+import (
+	"testing"
+
+	validation "github.com/go-ozzo/ozzo-validation"
+	version "github.com/hashicorp/go-version"
+	"github.com/runatlantis/atlantis/server/events/yaml/valid"
+	. "github.com/runatlantis/atlantis/testing"
+)
+
+func TestConfig_FindProjectsByDir(t *testing.T) {
+	tfVersion, _ := version.NewVersion("v0.11.0")
+	cases := []struct {
+		description string
+		nameRegex   string
+		input       valid.RepoCfg
+		expProjects []valid.Project
+	}{
+		{
+			description: "Find projects with 'dev' prefix as allowed prefix",
+			nameRegex:   "dev.*",
+			input: valid.RepoCfg{
+				Version: 3,
+				Projects: []valid.Project{
+					{
+						Dir:              ".",
+						Name:             String("dev_terragrunt_myproject"),
+						Workspace:        "myworkspace",
+						TerraformVersion: tfVersion,
+						Autoplan: valid.Autoplan{
+							WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+							Enabled:      false,
+						},
+						ApplyRequirements: []string{"approved"},
+					},
+				},
+				Workflows: map[string]valid.Workflow{
+					"myworkflow": {
+						Name:        "myworkflow",
+						Apply:       valid.DefaultApplyStage,
+						Plan:        valid.DefaultPlanStage,
+						PolicyCheck: valid.DefaultPolicyCheckStage,
+					},
+				},
+				AllowedRegexpPrefixes: []string{"dev", "staging"},
+			},
+			expProjects: []valid.Project{
+				{
+					Dir:              ".",
+					Name:             String("dev_terragrunt_myproject"),
+					Workspace:        "myworkspace",
+					TerraformVersion: tfVersion,
+					Autoplan: valid.Autoplan{
+						WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+						Enabled:      false,
+					},
+					ApplyRequirements: []string{"approved"},
+				},
+			},
+		},
+		{
+			description: "Only find projects with allowed prefix",
+			nameRegex:   ".*",
+			input: valid.RepoCfg{
+				Version: 3,
+				Projects: []valid.Project{
+					{
+						Dir:              ".",
+						Name:             String("dev_terragrunt_myproject"),
+						Workspace:        "myworkspace",
+						TerraformVersion: tfVersion,
+						Autoplan: valid.Autoplan{
+							WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+							Enabled:      false,
+						},
+						ApplyRequirements: []string{"approved"},
+					},
+					{
+						Dir:              ".",
+						Name:             String("staging_terragrunt_myproject"),
+						Workspace:        "myworkspace",
+						TerraformVersion: tfVersion,
+						Autoplan: valid.Autoplan{
+							WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+							Enabled:      false,
+						},
+						ApplyRequirements: []string{"approved"},
+					},
+				},
+				Workflows: map[string]valid.Workflow{
+					"myworkflow": {
+						Name:        "myworkflow",
+						Apply:       valid.DefaultApplyStage,
+						Plan:        valid.DefaultPlanStage,
+						PolicyCheck: valid.DefaultPolicyCheckStage,
+					},
+				},
+				AllowedRegexpPrefixes: []string{"dev", "staging"},
+			},
+			expProjects: nil,
+		},
+		{
+			description: "Find all projects without restrictions of allowed prefix",
+			nameRegex:   ".*",
+			input: valid.RepoCfg{
+				Version: 3,
+				Projects: []valid.Project{
+					{
+						Dir:              ".",
+						Name:             String("dev_terragrunt_myproject"),
+						Workspace:        "myworkspace",
+						TerraformVersion: tfVersion,
+						Autoplan: valid.Autoplan{
+							WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+							Enabled:      false,
+						},
+						ApplyRequirements: []string{"approved"},
+					},
+					{
+						Dir:              ".",
+						Name:             String("staging_terragrunt_myproject"),
+						Workspace:        "myworkspace",
+						TerraformVersion: tfVersion,
+						Autoplan: valid.Autoplan{
+							WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+							Enabled:      false,
+						},
+						ApplyRequirements: []string{"approved"},
+					},
+				},
+				Workflows: map[string]valid.Workflow{
+					"myworkflow": {
+						Name:        "myworkflow",
+						Apply:       valid.DefaultApplyStage,
+						Plan:        valid.DefaultPlanStage,
+						PolicyCheck: valid.DefaultPolicyCheckStage,
+					},
+				},
+				AllowedRegexpPrefixes: nil,
+			},
+			expProjects: []valid.Project{
+				{
+					Dir:              ".",
+					Name:             String("dev_terragrunt_myproject"),
+					Workspace:        "myworkspace",
+					TerraformVersion: tfVersion,
+					Autoplan: valid.Autoplan{
+						WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+						Enabled:      false,
+					},
+					ApplyRequirements: []string{"approved"},
+				},
+				{
+					Dir:              ".",
+					Name:             String("staging_terragrunt_myproject"),
+					Workspace:        "myworkspace",
+					TerraformVersion: tfVersion,
+					Autoplan: valid.Autoplan{
+						WhenModified: []string{"**/*.tf*", "**/terragrunt.hcl"},
+						Enabled:      false,
+					},
+					ApplyRequirements: []string{"approved"},
+				},
+			},
+		},
+	}
+	validation.ErrorTag = "yaml"
+	for _, c := range cases {
+		t.Run(c.description, func(t *testing.T) {
+			projects := c.input.FindProjectsByName(c.nameRegex)
+			Equals(t, c.expProjects, projects)
+		})
+	}
+}