diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index ec567ed..63a6983 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -202,7 +202,7 @@ def complete_prefix_number_ordering(entries):
         version = next(ver for ver in (ALT_VERSIONS + ['']) if ver in entry.name)
         entries_by_version.setdefault(version, []).append(entry)
 
-    numberings_by_version = {ver: prefix_numbering(entries_by_version[ver]) for ver in entries_by_version}
+    numberings_by_version = {ver: unique_hierarchical_prefix_numbering(entries_by_version[ver]) for ver in entries_by_version}
 
     unified_indices = set()
     for numbering in numberings_by_version.values():
@@ -212,8 +212,15 @@ def complete_prefix_number_ordering(entries):
     unified_indices = list(unified_indices)
     unified_indices.sort()
 
-    if len(unified_indices) > 1 and min(unified_indices[i] - unified_indices[i-1] for i in range(1, len(unified_indices))) > 2:
-        return None
+    if len(unified_indices) > 1:
+        for i in range(1, len(unified_indices)):
+            cur = unified_indices[i]
+            prev = unified_indices[i-1]
+            for level in range(min(len(cur), len(prev))):
+                if cur[level] != prev[level]:
+                    if cur[level] - prev[level] > 2:
+                        return None
+                    break
 
     versions = list(numberings_by_version.keys())
     versions.sort()
@@ -231,27 +238,37 @@ def complete_prefix_number_ordering(entries):
     for out_ver in outer_versions:
         for i in unified_indices:
             for ver in ([out_ver] + (inner_versions if out_ver == versions[0] else [])):
-                entries_i_ver = numberings_by_version[ver].get(i, [])
-                if len(entries_i_ver) <= 1:
-                    result += entries_i_ver
-                else:
-                    return None
+                result += numberings_by_version[ver].get(i, [])
     return result
 
-def prefix_numbering(entries):
+def unique_hierarchical_prefix_numbering(entries, start_point=0):
     matches = reversed(list(NUMBER_REGEX.finditer(entries[0].name)))
     for m in matches:
         pos = m.start()
+        if pos < start_point:
+            return None
         prefix = entries[0].name[:pos]
         if all(e.name.startswith(prefix) for e in entries):
-            entries_by_index = {}
+            numbering = {}
             for e in entries:
                 n = NUMBER_REGEX.match(e.name[pos:])
                 if n is None:
                     return None
                 i = int(n.group())
-                entries_by_index.setdefault(i, []).append(e)
-            return entries_by_index
+                numbering.setdefault((i,), []).append(e)
+
+            indices = list(numbering.keys())
+            for idx in indices:
+                if len(numbering[idx]) > 1:
+                    ents_idx = numbering.pop(idx)
+                    next_layer_start = pos + NUMBER_REGEX.match(ents_idx[0].name[pos:]).end()
+                    sub_numbering = unique_hierarchical_prefix_numbering(ents_idx, start_point=next_layer_start)
+                    if not sub_numbering:
+                        return None
+                    for sub_idx in sub_numbering:
+                        numbering[(*idx, *sub_idx)] = sub_numbering[sub_idx]
+
+            return numbering
 
     return None