diff --git a/xarray/backends/h5netcdf_.py b/xarray/backends/h5netcdf_.py
index d55fac4f6c9..4c36adbc121 100644
--- a/xarray/backends/h5netcdf_.py
+++ b/xarray/backends/h5netcdf_.py
@@ -425,18 +425,22 @@ def open_dataset(  # type: ignore[override]  # allow LSP violation, not supporti
         return ds
 
     # TODO [MHS, 01/23/2024] This is duplicative of the netcdf4 code in an ugly way.
-    def open_datatree(self, filename: str, **kwargs) -> DataTree:
+    def open_datatree(
+        self,
+        filename_or_obj: str | os.PathLike[Any] | BufferedIOBase | AbstractDataStore,
+        **kwargs,
+    ) -> DataTree:
         from h5netcdf.legacyapi import Dataset as ncDataset
 
         from xarray.backends.api import open_dataset
         from xarray.datatree_.datatree import DataTree
         from xarray.datatree_.datatree.treenode import NodePath
 
-        ds = open_dataset(filename, **kwargs)
+        ds = open_dataset(filename_or_obj, **kwargs)
         tree_root = DataTree.from_dict({"/": ds})
-        with ncDataset(filename, mode="r") as ncds:
+        with ncDataset(filename_or_obj, mode="r") as ncds:
             for path in _iter_nc_groups(ncds):
-                subgroup_ds = open_dataset(filename, group=path, **kwargs)
+                subgroup_ds = open_dataset(filename_or_obj, group=path, **kwargs)
 
                 # TODO refactor to use __setitem__ once creation of new nodes by assigning Dataset works again
                 node_name = NodePath(path).name
diff --git a/xarray/backends/netCDF4_.py b/xarray/backends/netCDF4_.py
index d7879a57264..8c3bf0ff77c 100644
--- a/xarray/backends/netCDF4_.py
+++ b/xarray/backends/netCDF4_.py
@@ -668,18 +668,22 @@ def open_dataset(  # type: ignore[override]  # allow LSP violation, not supporti
             )
         return ds
 
-    def open_datatree(self, filename: str, **kwargs) -> DataTree:
+    def open_datatree(
+        self,
+        filename_or_obj: str | os.PathLike[Any] | BufferedIOBase | AbstractDataStore,
+        **kwargs,
+    ) -> DataTree:
         from netCDF4 import Dataset as ncDataset
 
         from xarray.backends.api import open_dataset
         from xarray.datatree_.datatree import DataTree
         from xarray.datatree_.datatree.treenode import NodePath
 
-        ds = open_dataset(filename, **kwargs)
+        ds = open_dataset(filename_or_obj, **kwargs)
         tree_root = DataTree.from_dict({"/": ds})
-        with ncDataset(filename, mode="r") as ncds:
+        with ncDataset(filename_or_obj, mode="r") as ncds:
             for path in _iter_nc_groups(ncds):
-                subgroup_ds = open_dataset(filename, group=path, **kwargs)
+                subgroup_ds = open_dataset(filename_or_obj, group=path, **kwargs)
 
                 # TODO refactor to use __setitem__ once creation of new nodes by assigning Dataset works again
                 node_name = NodePath(path).name
diff --git a/xarray/backends/zarr.py b/xarray/backends/zarr.py
index bb46ab68de5..a276103b18b 100644
--- a/xarray/backends/zarr.py
+++ b/xarray/backends/zarr.py
@@ -1036,19 +1036,25 @@ def open_dataset(  # type: ignore[override]  # allow LSP violation, not supporti
             )
         return ds
 
-    def open_datatree(self, store, **kwargs) -> DataTree:
-        import zarr  # type: ignore
+    def open_datatree(
+        self,
+        filename_or_obj: str | os.PathLike[Any] | BufferedIOBase | AbstractDataStore,
+        **kwargs,
+    ) -> DataTree:
+        import zarr
 
         from xarray.backends.api import open_dataset
         from xarray.datatree_.datatree import DataTree
         from xarray.datatree_.datatree.treenode import NodePath
 
-        zds = zarr.open_group(store, mode="r")
-        ds = open_dataset(store, engine="zarr", **kwargs)
+        zds = zarr.open_group(filename_or_obj, mode="r")
+        ds = open_dataset(filename_or_obj, engine="zarr", **kwargs)
         tree_root = DataTree.from_dict({"/": ds})
         for path in _iter_zarr_groups(zds):
             try:
-                subgroup_ds = open_dataset(store, engine="zarr", group=path, **kwargs)
+                subgroup_ds = open_dataset(
+                    filename_or_obj, engine="zarr", group=path, **kwargs
+                )
             except zarr.errors.PathNotFoundError:
                 subgroup_ds = Dataset()