---
title: IHierarchialLevel
summary: API reference for IHierarchialLevel.
status: draft
owner: SAIF Doc Gen
last_reviewed: 2026-09-15
library: SAIF.Framework.Common.Files
reference_type: package
---

# IHierarchialLevel

`IHierarchialLevel` is the contract implemented by `HierarchialLevel`; it extends `ISegmentGroup` with the HL-rooted `LevelData`/`HierarchySegment` surface required to model one hierarchical level nested within a hierarchical transaction ([BR-035](../../business-rules.md#br-035-hierarchical-levels-nested-inside-hierarchical-transaction)).

## Purpose
- Declares the typed `LevelData` (HL) accessor, raw `HierarchySegment`, and member `Segments` that any hierarchical-level implementation must provide.

## Context
- Namespace: `SAIF.Common.Files.Edi`
- Assembly/package: `SAIF.Framework.Common.Files`
- Extends: `ISegmentGroup`

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| LevelData | `HlSegment LevelData { get; }` | The strongly-typed HL segment for this hierarchical level. |
| HierarchySegment | `IEdiSegment HierarchySegment { get; }` | The raw HL segment used as the source for `LevelData`. |
| Segments | `IEnumerable<IEdiSegment> Segments { get; }` | This level's member segments with control segments excluded ([BR-033](../../business-rules.md#br-033-control-segments-excluded-from-member-segments-collections)). |

## Inherited public members

Members in this section are inherited from `ISegmentGroup` in `SAIF.Framework.Common.Files`. They are available on this type through inheritance.

| Member | Signature | Purpose | Origin |
| --- | --- | --- | --- |
| Index | `int Index { get; set; }` | The sequential ordinal assigned to this level among its siblings. | `SAIF.Framework.Common.Files` — `ISegmentGroup` |
| Key | `string Key { get; set; }` | The HL01 hierarchical ID number value that uniquely identifies this level ([BR-034](../../business-rules.md#br-034-group-keys-derived-from-control-number-elements)). | `SAIF.Framework.Common.Files` — `ISegmentGroup` |
| SegmentGroupId | `string SegmentGroupId { get; set; }` | The segment tag (`"HL"`) that this group was delimited by during parsing. | `SAIF.Framework.Common.Files` — `ISegmentGroup` |
| Level | `int Level { get; set; }` | The nesting depth of this group. | `SAIF.Framework.Common.Files` — `ISegmentGroup` |

## Sources
- Common\SAIF.Common.Files\Edi\IHierarchialLevel.cs