Reading the BiBlend view in a Spreadsheet (TableView) business rule

Here's some code that works for me on 7.2.2. HOWEVER, as I was testing it, it looked like OneStream had some issue with a particular column (an Attribute), so maybe try restricting to a few columns to test the connection first.

Namespace OneStream.BusinessRule.Spreadsheet.GL_TestForum
  Public Class MainClass
    Public Function Main(ByVal si As SessionInfo, ByVal globals As BRGlobals, _
	       ByVal api As Object, ByVal args As SpreadsheetArgs) As Object
        Try
			Select Case args.FunctionType
				
				Case Is = SpreadsheetFunctionType.Unknown
					
				Case Is = SpreadsheetFunctionType.GetCustomSubstVarsInUse
					
				Case Is = SpreadsheetFunctionType.GetTableView
					Dim dtable As DataTable
					Using dbconnapp As DbConnInfo = BRApi.Database.CreateExternalDbConnInfo(si, "AnalyticBlendExternal")
						dtable = BRApi.Database.ExecuteSql(dbconnapp, _
							"SELECT TOP 10 [Rt],[SourceID],[Label],[TextValue],[sEntity] FROM vBIB_Gold_AnalyticBlend_Trainer_BlendImport_Blend_2020M1", _
							False)
						dTable.TableName = "BiBLend"
					End Using
					Return Me.getTv(si, globals, args, dTable)
				Case Is = SpreadsheetFunctionType.SaveTableView
					
			End Select

			Return Nothing
		Catch ex As Exception
			Throw ErrorHandler.LogWrite(si, New XFException(si, ex))
		End Try
    End Function
        
    Public Function getTv(ByVal si As SessionInfo, ByVal globals As BRGlobals, _
		    ByVal args As SpreadsheetArgs, ByVal dt As DataTable) As TableView
		Dim tv As New TableView()
		tv.CanModifyData = False
		Dim rowHeader As New TableViewRow()
		For Each dc As DataColumn In dt.Columns
			Dim col As New TableViewColumn()
			col.Name = dc.ColumnName
			col.Value = dc.ColumnName
			col.IsHeader = True
			tv.Columns.add(col)
			rowHeader.Items.Add(col.Name, col)
			
		Next
		
		tv.Rows.Add(rowHeader)
		For Each row As DataRow In dt.Rows
			Dim tvRow As New TableViewRow()
			For Each column As TableViewColumn In tv.Columns
				tvRow.Items.Add(column.Name, _
					tv.CreateColumn(column.Name, row.Item(column.Name), False))
			Next
			tv.Rows.Add(tvRow)
		Next
		Return tv
	End Function
  End Class
End Namespace

Side note: please don't do this, it's a recipe for problems:

For Each DataColumn as DataColumn in dt.Columns

 You're relying on Vb's rules for resolving names, which can be surprising at times. Just give a new name to that variable:

For Each datacol as DataColumn in dt.Columns