Referencing previous sheet in macro for excel chart
ActiveChart.SeriesCollection(1).Name = "='ActiveChart.Next.Select'!$B$1"

ActiveChart.SeriesCollection(1).Name = "=Sheets(1)!$B$1"

=Sheet1!A1

Dim ws As Worksheet
Dim formula As String

Set ws = ActiveSheet.Next
formula = "=" & ws.name & "!A1"

ActiveChart.SeriesCollection(1).name = formula