Assets are created in the Package folders when creating assets via custom buttons in the Inspector window or other windows

Steps to reproduce:

1. Create a new project using the High Definition 3D template
2. Create a new Decal Projector GameObject (GameObject > Rendering > HDRP Decal Projector)
3. Select the newly created Decal Projector GameObject in the Hierarchy window
4. Click on the "DefaultHDDecalMaterial" in the Inspector window under the HDRP Decal Projector component
5. Click the "New" button and select "HDRP Decal"
6. Press Enter
7. Observe the Editor

Actual results: The Asset is created in a Package folder, and "New HDRP Decal.mat has no meta file, but it's in an immutable folder.", "Render Graph Execution error", "InvalidOperationException: Material needs to enable instancing for use with DrawMeshInstanced." errors are thrown

Expected results: The Asset is created in the Assets folder

Reproducible with versions: 6000.0.69f1, 6000.3.10f1, 6000.4.0b11, 6000.5.0a8

Tested on (OS): MacOS Silicon Tahoe 26.2

Note: 

1. The Project Browser needs to be in two column mode.
2. The path Packages/com.unity.render-pipelines.high-definition/Runtime/RenderPipelineResources/Material needs to be selected in the Project Browser

The Project Browser includes a specific bug fix (presumably fogbugz) case 550484 that selects the currently open directory to create a new Asset in, in this specific mode, in ValidateCreateNewAssetPath

The [Internal link] specifies a name for the new Asset, rather than a path, delegating the task of selecting a path to the Unity code.