docs: add UI/UX Improvements report for v3.0.0

docs/features/opensearch-dashboards/dashboards-ui-ux-fixes.md

@@ -67,6 +67,7 @@ graph TB
 #### Navigation Fixes
 - **Nav Group Assignment**: Fixed visualization pages showing incorrect nav group when workspace is disabled
 - **Sample Data Category**: Moved sample data from "Custom" to "Settings and Setup" category
+- **Sidecar Compatibility**: Fixed navigation icon positioning when sidecar panel is docked to the left
 
 #### Query Editor Fixes
 - **Suggestions Popup**: Fixed suggestions not closing after pressing Enter to submit query
@@ -86,6 +87,9 @@ graph TB
 - Replaced `@elastic/filesaver` with `file-saver` library
 - Replaced `formatNumWithCommas` with native `toLocaleString()`
 
+#### Data Frame Fixes
+- **Null/Undefined Handling**: Fixed TypeError when processing data frames with null or undefined values in nested object fields
+
 ## Limitations
 
 - UI fixes are incremental improvements
@@ -96,6 +100,8 @@ graph TB
 
 | Version | PR | Description |
 |---------|-----|-------------|
+| v3.0.0 | [#9514](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9514) | Make nav icon style compatible with sidecar |
+| v3.0.0 | [#9516](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9516) | Fix data frame null or undefined object conversion error |
 | v3.0.0 | [#9665](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9665) | Fix workspace disabled navigation |
 | v3.0.0 | [#9666](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9666) | Close suggestions after query submission |
 | v3.0.0 | [#9668](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9668) | Fix dataset selector flashing |

docs/releases/v3.0.0/features/opensearch-dashboards/ui-ux-improvements.md

@@ -0,0 +1,95 @@
+# UI/UX Improvements
+
+## Summary
+
+OpenSearch Dashboards v3.0.0 includes two UI/UX bug fixes that improve navigation compatibility with the sidecar panel and fix data frame conversion errors when handling null or undefined values.
+
+## Details
+
+### What's New in v3.0.0
+
+#### Navigation Icon Sidecar Compatibility
+
+Fixed an issue where the navigation toggle icon was not properly positioned when the sidecar panel (e.g., chatbot) was docked to the left side of the screen.
+
+**Problem**: The navigation toggle button used a fixed position with `left: 0`, which caused it to overlap with the sidecar panel when docked to the left.
+
+**Solution**: Added dynamic left positioning based on sidecar configuration. When the sidecar is docked to the left, the navigation icon adjusts its position to account for the sidecar width.
+
+```mermaid
+graph LR
+    subgraph "Before Fix"
+        A1[Sidecar Left] --> B1[Nav Icon Overlaps]
+    end
+    subgraph "After Fix"
+        A2[Sidecar Left] --> B2[Nav Icon Offset]
+    end
+```
+
+#### Data Frame Null/Undefined Conversion Fix
+
+Fixed a TypeError that occurred when processing data frames containing null or undefined values in nested object fields.
+
+**Problem**: The `processNestedFieldEntry` function called `Object.entries()` on values without checking for null/undefined, causing "Cannot convert undefined or null to object" errors.
+
+**Solution**: Added a null check before calling `Object.entries()`, returning the value directly when it's falsy.
+
+```typescript
+// Before (caused error)
+Object.entries(value).forEach(...)
+
+// After (fixed)
+if (!value) {
+  return value;
+}
+Object.entries(value).forEach(...)
+```
+
+### Technical Changes
+
+#### New Components
+
+| Component | Description |
+|-----------|-------------|
+| `getSidecarLeftNavStyle` | Helper function to calculate left offset for nav elements when sidecar is docked left |
+
+#### Changed Files
+
+| File | Change |
+|------|--------|
+| `src/core/public/overlays/sidecar/helper.ts` | Added `getSidecarLeftNavStyle` function |
+| `src/core/public/chrome/ui/header/header.tsx` | Applied sidecar left nav style to toggle button |
+| `src/core/public/chrome/ui/header/collapsible_nav_group_enabled.scss` | Changed `.searchBarIcon` from `fixed` to `relative` position |
+| `src/plugins/data/common/data_frames/utils.ts` | Added null check in `processNestedFieldEntry` |
+
+### Usage Example
+
+The sidecar left nav style helper:
+
+```typescript
+import { getSidecarLeftNavStyle } from '../../../overlays';
+
+// Returns { left: paddingSize } when sidecar is docked left
+// Returns {} otherwise
+const style = getSidecarLeftNavStyle(sidecarConfig);
+```
+
+## Limitations
+
+- Navigation icon positioning only applies when sidecar is docked to the left
+- The null check fix applies to all nested object fields in data frames
+
+## Related PRs
+
+| PR | Description |
+|----|-------------|
+| [#9514](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9514) | Make nav icon style compatible with sidecar |
+| [#9516](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/9516) | Fix data frame null or undefined object conversion error |
+
+## References
+
+- [OpenSearch Dashboards Repository](https://github.com/opensearch-project/OpenSearch-Dashboards)
+
+## Related Feature Report
+
+- [Full feature documentation](../../../../features/opensearch-dashboards/dashboards-ui-ux-fixes.md)

docs/releases/v3.0.0/index.md

@@ -15,6 +15,7 @@
 - [Dashboards CI/CD & Documentation](features/opensearch-dashboards/dashboards-ci-cd-documentation.md)
 - [Dashboards Cypress Testing](features/opensearch-dashboards/dashboards-cypress-testing.md)
 - [Dashboards UI/UX Fixes](features/opensearch-dashboards/dashboards-ui-ux-fixes.md)
+- [UI/UX Improvements](features/opensearch-dashboards/ui-ux-improvements.md)
 
 ## sql