diff --git a/hugofs/component_fs.go b/hugofs/component_fs.go
index ec7f06a07..e59b595c7 100644
--- a/hugofs/component_fs.go
+++ b/hugofs/component_fs.go
@@ -320,8 +320,9 @@ func (fs *componentFs) applyMeta(fi FileNameIsDir, name string) (FileMetaInfo, b
 
 	meta.PathInfo = pi
 	if !fim.IsDir() {
+		pp := fs.opts.Cfg.PathParser()
 		if fileLang := meta.PathInfo.Lang(); fileLang != "" {
-			if idx, ok := fs.opts.Cfg.PathParser().LanguageIndex[fileLang]; ok {
+			if idx, ok := pp.LanguageIndex[fileLang]; ok {
 				// A valid lang set in filename.
 				// Give priority to myfile.sv.txt inside the sv filesystem.
 				meta.Weight++
@@ -330,7 +331,29 @@ func (fs *componentFs) applyMeta(fi FileNameIsDir, name string) (FileMetaInfo, b
 					// Not the default language, add some weight.
 					meta.SitesMatrix = sitesmatrix.NewWeightedVectorStore(meta.SitesMatrix, 10)
 				}
-
+			}
+		}
+		// Filename identifiers for roles/versions replace any mount configuration for that dimension.
+		if roles := pi.Roles(); len(roles) > 0 {
+			var indices []int
+			for _, role := range roles {
+				if idx := pp.ConfiguredDimensions.ConfiguredRoles.ResolveIndex(role); idx >= 0 {
+					indices = append(indices, idx)
+				}
+			}
+			if len(indices) > 0 {
+				meta.SitesMatrix = meta.SitesMatrix.WithRoleIndices(indices...)
+			}
+		}
+		if versions := pi.Versions(); len(versions) > 0 {
+			var indices []int
+			for _, version := range versions {
+				if idx := pp.ConfiguredDimensions.ConfiguredVersions.ResolveIndex(version); idx >= 0 {
+					indices = append(indices, idx)
+				}
+			}
+			if len(indices) > 0 {
+				meta.SitesMatrix = meta.SitesMatrix.WithVersionIndices(indices...)
 			}
 		}
 		switch meta.Component {
@@ -341,7 +364,6 @@ func (fs *componentFs) applyMeta(fi FileNameIsDir, name string) (FileMetaInfo, b
 				meta.Weight--
 			}
 		}
-
 	}
 
 	if fi.IsDir() {
diff --git a/hugolib/sitesmatrix/dimensions.go b/hugolib/sitesmatrix/dimensions.go
index d7a96a038..aefa6f5e0 100644
--- a/hugolib/sitesmatrix/dimensions.go
+++ b/hugolib/sitesmatrix/dimensions.go
@@ -214,7 +214,9 @@ type VectorProvider interface {
 type VectorStore interface {
 	VectorProvider
 	Complement(...VectorProvider) VectorStore
-	WithLanguageIndices(i int) VectorStore
+	WithLanguageIndices(i ...int) VectorStore
+	WithVersionIndices(i ...int) VectorStore
+	WithRoleIndices(i ...int) VectorStore
 	HasLanguage(lang int) bool
 	HasVersion(version int) bool
 	HasRole(role int) bool
diff --git a/hugolib/sitesmatrix/sitematrix_integration_test.go b/hugolib/sitesmatrix/sitematrix_integration_test.go
index 84908a190..e76e2b7aa 100644
--- a/hugolib/sitesmatrix/sitematrix_integration_test.go
+++ b/hugolib/sitesmatrix/sitematrix_integration_test.go
@@ -1901,3 +1901,55 @@ title: p1 de
 </ul>
 	`)
 }
+
+// Issue 14756.
+func TestFilenameIdentifierShouldReplaceMountDimension(t *testing.T) {
+	t.Parallel()
+	files := `
+-- hugo.toml --
+baseURL = "https://example.org/"
+disableKinds = ["taxonomy", "term", "rss", "sitemap"]
+defaultContentLanguage = "en"
+defaultContentRole = "guest"
+defaultContentRoleInSubdir = true
+[roles]
+[roles.guest]
+weight = 100
+[roles.member]
+weight = 200
+[module]
+[[module.mounts]]
+source = 'content/member'
+target = 'content'
+[module.mounts.sites.matrix]
+roles = "member"
+[[module.mounts]]
+source = 'content/guest'
+target = 'content'
+[module.mounts.sites.matrix]
+roles = "*"
+-- content/member/bundle/index.md --
+---
+title: "Bundle"
+---
+-- content/guest/bundle/index.md --
+---
+title: "Bundle"
+---
+-- content/guest/bundle/img._role_member_.txt --
+memberimg
+-- content/guest/bundle/guestimg.txt --
+guestimg
+-- layouts/page.html --
+Role: {{ .Site.Role.Name }}|{{ range .Resources }}{{ .Name }}|{{ end }}$
+-- layouts/list.html --
+List.
+`
+
+	b := hugolib.Test(t, files)
+
+	// The guest role should only see guestimg.txt (not img._role_member_.txt).
+	b.AssertFileContent("public/guest/bundle/index.html", "Role: guest|guestimg.txt|$")
+	// The member role should see both.
+	b.AssertFileContent("public/member/bundle/index.html", "Role: member|guestimg.txt|img._role_member_.txt|$")
+}
diff --git a/hugolib/sitesmatrix/vectorstores.go b/hugolib/sitesmatrix/vectorstores.go
index 174dd6ea9..b865bea65 100644
--- a/hugolib/sitesmatrix/vectorstores.go
+++ b/hugolib/sitesmatrix/vectorstores.go
@@ -209,17 +209,46 @@ func (s *vectorStoreMap) Vectors() []Vector {
 	return vectors
 }
 
-func (s *vectorStoreMap) WithLanguageIndices(i int) VectorStore {
+func (s *vectorStoreMap) WithLanguageIndices(i ...int) VectorStore {
 	c := s.clone()
 
 	for v := range c.sets {
-		v[Language] = i
-		c.sets[v] = struct{}{}
+		for _, i := range i {
+			nv := v
+			nv[Language] = i
+			c.sets[nv] = struct{}{}
+		}
 	}
 
 	return c
 }
 
+func (s *vectorStoreMap) WithVersionIndices(indices ...int) VectorStore {
+	old := s.clone()
+	c := newVectorStoreMap(len(old.sets) * len(indices))
+	for v := range old.sets {
+		for _, i := range indices {
+			nv := v
+			nv[Version] = i
+			c.sets[nv] = struct{}{}
+		}
+	}
+	return c
+}
+
+func (s *vectorStoreMap) WithRoleIndices(indices ...int) VectorStore {
+	old := s.clone()
+	c := newVectorStoreMap(len(old.sets) * len(indices))
+	for v := range old.sets {
+		for _, i := range indices {
+			nv := v
+			nv[Role] = i
+			c.sets[nv] = struct{}{}
+		}
+	}
+	return c
+}
+
 func (s *vectorStoreMap) HasLanguage(i int) bool {
 	for v := range s.sets {
 		if v.Language() == i {
@@ -589,10 +618,24 @@ func (s IntSets) shallowClone() *IntSets {
 	return &s
 }
 
-// WithLanguageIndices replaces the current language set with a single language index.
-func (s *IntSets) WithLanguageIndices(i int) VectorStore {
+// WithLanguageIndices replaces the current language set with the given language indices.
+func (s *IntSets) WithLanguageIndices(indices ...int) VectorStore {
 	c := s.shallowClone()
-	c.languages = hmaps.NewOrderedIntSet(i)
+	c.languages = hmaps.NewOrderedIntSet(indices...)
+	return c.init()
+}
+
+// WithVersionIndices replaces the current version set with the given version indices.
+func (s *IntSets) WithVersionIndices(indices ...int) VectorStore {
+	c := s.shallowClone()
+	c.versions = hmaps.NewOrderedIntSet(indices...)
+	return c.init()
+}
+
+// WithRoleIndices replaces the current role set with the given role indices.
+func (s *IntSets) WithRoleIndices(indices ...int) VectorStore {
+	c := s.shallowClone()
+	c.roles = hmaps.NewOrderedIntSet(indices...)
 	return c.init()
 }