Bookmark navigation in SfPdfViewer
Use the bookmark panel to jump directly to labeled destinations in a PDF.
Bookmarks defined in the PDF document are automatically loaded and listed in the bookmark panel. Selecting a bookmark navigates to its target. Nested bookmarks are supported; if the document has no bookmarks, the panel appears empty.

Enable or disable the bookmark panel by setting the EnableBookmarkPanel property. This property only controls the panel’s visibility; bookmarks are read from the PDF.
@using Syncfusion.Blazor.SfPdfViewer
<SfPdfViewer2 Height="100%" Width="100%" DocumentPath="@DocumentPath" EnableBookmarkPanel="true" />
@code{
public string DocumentPath { get; set; } = "wwwroot/Data/PDF_Succinctly.pdf";
}