diff --git a/services/storage/src/simcore_service_storage/exceptions/errors.py b/services/storage/src/simcore_service_storage/exceptions/errors.py
index 5856a2fec5b7..93dc85ddcd31 100644
--- a/services/storage/src/simcore_service_storage/exceptions/errors.py
+++ b/services/storage/src/simcore_service_storage/exceptions/errors.py
@@ -1,8 +1,7 @@
 from common_library.errors_classes import OsparcErrorMixin
 
 
-class StorageRuntimeError(OsparcErrorMixin, RuntimeError):
-    ...
+class StorageRuntimeError(OsparcErrorMixin, RuntimeError): ...
 
 
 class ConfigurationError(StorageRuntimeError):
@@ -45,3 +44,7 @@ class InvalidFileIdentifierError(AccessLayerError):
 
 class DatCoreCredentialsMissingError(StorageRuntimeError):
     msg_template: str = "DatCore credentials are incomplete. TIP: Check your settings"
+
+
+class SelectionNotAllowedError(StorageRuntimeError):
+    msg_template: str = "Selection='{selection}' must be from the same folder"
diff --git a/services/storage/src/simcore_service_storage/simcore_s3_dsm.py b/services/storage/src/simcore_service_storage/simcore_s3_dsm.py
index 671d9d01cee6..616571176371 100644
--- a/services/storage/src/simcore_service_storage/simcore_s3_dsm.py
+++ b/services/storage/src/simcore_service_storage/simcore_s3_dsm.py
@@ -61,6 +61,7 @@
     LinkAlreadyExistsError,
     ProjectAccessRightError,
     ProjectNotFoundError,
+    SelectionNotAllowedError,
 )
 from .models import (
     DatasetMetaData,
@@ -81,9 +82,11 @@
 from .modules.s3 import get_s3_client
 from .utils.s3_utils import S3TransferDataCB
 from .utils.simcore_s3_dsm_utils import (
+    UserSelectionStr,
     compute_file_id_prefix,
     create_and_upload_export,
     create_random_export_name,
+    ensure_user_selection_from_same_base_directory,
     expand_directory,
     get_accessible_project_ids,
     get_directory_file_id,
@@ -1249,7 +1252,11 @@ async def create_s3_export(
         *,
         progress_bar: ProgressBarData,
     ) -> StorageFileID:
-        source_object_keys: set[StorageFileID] = set()
+        source_object_keys: set[tuple[UserSelectionStr, StorageFileID]] = set()
+
+        # ensure all selected items have the same parent
+        if not ensure_user_selection_from_same_base_directory(object_keys):
+            raise SelectionNotAllowedError(selection=object_keys)
 
         # check access rights
         for object_key in object_keys:
@@ -1279,7 +1286,7 @@ async def create_s3_export(
                 self.simcore_bucket_name, object_key
             ):
                 for entry in meta_data_files:
-                    source_object_keys.add(entry.object_key)
+                    source_object_keys.add((object_key, entry.object_key))
 
         _logger.debug(
             "User selection '%s' includes '%s' files",
diff --git a/services/storage/src/simcore_service_storage/utils/simcore_s3_dsm_utils.py b/services/storage/src/simcore_service_storage/utils/simcore_s3_dsm_utils.py
index 5ebe83c486b1..5764151fdf12 100644
--- a/services/storage/src/simcore_service_storage/utils/simcore_s3_dsm_utils.py
+++ b/services/storage/src/simcore_service_storage/utils/simcore_s3_dsm_utils.py
@@ -1,10 +1,12 @@
 from contextlib import suppress
 from pathlib import Path
+from typing import TypeAlias
 from uuid import uuid4
 
 import orjson
 from aws_library.s3 import S3MetaData, SimcoreS3API
 from aws_library.s3._constants import STREAM_READER_CHUNK_SIZE
+from aws_library.s3._models import S3ObjectKey
 from models_library.api_schemas_storage.storage_schemas import S3BucketName
 from models_library.projects import ProjectID
 from models_library.projects_nodes_io import (
@@ -143,20 +145,40 @@ def create_random_export_name(user_id: UserID) -> StorageFileID:
     )
 
 
+def ensure_user_selection_from_same_base_directory(
+    object_keys: list[S3ObjectKey],
+) -> bool:
+    parents = [Path(x).parent for x in object_keys]
+    return len(set(parents)) <= 1
+
+
+UserSelectionStr: TypeAlias = str
+
+
+def _base_path_parent(base_path: UserSelectionStr, s3_object: S3ObjectKey) -> str:
+    base_path_parent_path = Path(base_path).parent
+    s3_object_path = Path(s3_object)
+    if base_path_parent_path == s3_object_path:
+        return s3_object_path.name
+
+    result = s3_object_path.relative_to(base_path_parent_path)
+    return f"{result}"
+
+
 async def create_and_upload_export(
     s3_client: SimcoreS3API,
     bucket: S3BucketName,
     *,
-    source_object_keys: set[StorageFileID],
+    source_object_keys: set[tuple[UserSelectionStr, StorageFileID]],
     destination_object_keys: StorageFileID,
     progress_bar: ProgressBarData,
 ) -> None:
     archive_entries: ArchiveEntries = [
         (
-            s3_object,
+            _base_path_parent(selection, s3_object),
             await s3_client.get_bytes_streamer_from_object(bucket, s3_object),
         )
-        for s3_object in source_object_keys
+        for (selection, s3_object) in source_object_keys
     ]
 
     async with progress_bar:
diff --git a/services/storage/tests/unit/test_rpc_handlers_simcore_s3.py b/services/storage/tests/unit/test_rpc_handlers_simcore_s3.py
index 3cd57155e29f..d7ed04de9b93 100644
--- a/services/storage/tests/unit/test_rpc_handlers_simcore_s3.py
+++ b/services/storage/tests/unit/test_rpc_handlers_simcore_s3.py
@@ -592,17 +592,20 @@ async def test_start_export_data(
 ):
     _, src_projects_list = await random_project_with_files(project_params)
 
-    paths_to_export: set[SimcoreS3FileID] = set()
+    all_available_files: set[SimcoreS3FileID] = set()
     for x in src_projects_list.values():
-        paths_to_export |= x.keys()
+        all_available_files |= x.keys()
+
+    nodes_in_project_to_export = {
+        TypeAdapter(PathToExport).validate_python("/".join(Path(x).parts[0:2]))
+        for x in all_available_files
+    }
 
     result = await _request_start_export_data(
         storage_rabbitmq_rpc_client,
         user_id,
         product_name,
-        paths_to_export=[
-            TypeAdapter(PathToExport).validate_python(x) for x in paths_to_export
-        ],
+        paths_to_export=list(nodes_in_project_to_export),
     )
 
     assert re.fullmatch(
diff --git a/services/storage/tests/unit/test_simcore_s3_dsm.py b/services/storage/tests/unit/test_simcore_s3_dsm.py
index df4d00e9db24..fdde44a86636 100644
--- a/services/storage/tests/unit/test_simcore_s3_dsm.py
+++ b/services/storage/tests/unit/test_simcore_s3_dsm.py
@@ -243,7 +243,11 @@ async def test_create_s3_export(
     cleanup_files_closure: Callable[[SimcoreS3FileID], None],
 ):
     initial_fmd_count = await _get_fmds_count(sqlalchemy_async_engine)
-    selection_to_export = _get_folder_and_files_selection(paths_for_export)
+    all_files_to_export = _get_folder_and_files_selection(paths_for_export)
+    selection_to_export = {
+        S3ObjectKey(project_id)
+        for project_id in {Path(p).parents[-2] for p in all_files_to_export}
+    }
 
     reports: list[ProgressReport] = []
 
diff --git a/services/storage/tests/unit/test_simcore_s3_dsm_utils.py b/services/storage/tests/unit/test_simcore_s3_dsm_utils.py
index 74c79a8cf364..56f7d9bd92af 100644
--- a/services/storage/tests/unit/test_simcore_s3_dsm_utils.py
+++ b/services/storage/tests/unit/test_simcore_s3_dsm_utils.py
@@ -1,5 +1,13 @@
+from pathlib import Path
+
 import pytest
-from simcore_service_storage.utils.simcore_s3_dsm_utils import compute_file_id_prefix
+from aws_library.s3._models import S3ObjectKey
+from simcore_service_storage.utils.simcore_s3_dsm_utils import (
+    UserSelectionStr,
+    _base_path_parent,
+    compute_file_id_prefix,
+    ensure_user_selection_from_same_base_directory,
+)
 
 
 @pytest.mark.parametrize(
@@ -19,3 +27,49 @@
 )
 def test_compute_file_id_prefix(file_id, levels, expected):
     assert compute_file_id_prefix(file_id, levels) == expected
+
+
+_FOLDERS_PATH = Path("nested/folders/path")
+
+
+@pytest.mark.parametrize(
+    "selection, s3_object, expected",
+    [
+        ("single_file", "single_file", "single_file"),
+        ("single_folder", "single_folder", "single_folder"),
+        ("a/b/c", "a/b/c/d/e/f/g", "c/d/e/f/g"),
+        (_FOLDERS_PATH / "folder", _FOLDERS_PATH / "folder", "folder"),
+        (_FOLDERS_PATH / "a_file.txt", _FOLDERS_PATH / "a_file.txt", "a_file.txt"),
+        (_FOLDERS_PATH, _FOLDERS_PATH / "with/some/content", "path/with/some/content"),
+    ],
+)
+def test__base_path_parent(selection: Path | str, s3_object: Path, expected: str):
+    assert (
+        _base_path_parent(UserSelectionStr(f"{selection}"), S3ObjectKey(f"{s3_object}"))
+        == expected
+    )
+
+
+@pytest.mark.parametrize(
+    "user_selection, expected",
+    [
+        ([], True),
+        (["folder"], True),
+        (["folder", "folder"], True),
+        (["", ""], True),
+        ([""], True),
+        ([_FOLDERS_PATH / "a", _FOLDERS_PATH / "b"], True),
+        (["a.txt", "b.txt"], True),
+        (["a/a.txt"], True),
+        # not same parent
+        (["firsta/file", "second/file"], False),
+        (["a/a.txt", "a.txt", "c.txt", "a/d.txt"], False),
+    ],
+)
+def test_ensure_user_selection_from_same_base_directory(
+    user_selection: list[S3ObjectKey | Path], expected: bool
+):
+    assert (
+        ensure_user_selection_from_same_base_directory([f"{x}" for x in user_selection])
+        == expected
+    )