Highlighting Duplicates across the work book in different ranges - with attachment

Which row header may have the duplicate values Company Name or Name of DM?
Do you want to check for the duplicate in the same range in all the sheets? i.e. if you enter a value in the range R5:D5 on Player 1 sheet, do you want to check for duplicates in the range 'Player 1'!D5:R5 TO 'Player 10'!D5:R5 only.

It would be helpful if you can input some sample values and highlight them manually to show the desired output.

This can be achieved with VBA.
Open your file --> Press Alt+F11 to open VBA Editor --> Double click ThisWorkbook from the project explorer on left side --> Paste the code given below in the opened code window --> Close VBA Editor --> Save your workbook as Excel Macro-Enabled Workbook.

Private Sub Workbook_SheetChange(ByVal sh As Object, ByVal Target As Range)
If Target.Count > 1 Then Exit Sub
Dim ws
If Target.Column >= 4 And Target.Column <= 18 And Target.Row > 4 Then
   Application.EnableEvents = False
   If Cells(Target.Row, "C") = "Company Name" Then
      If Target <> "" Then
         For Each ws In Array("Player 1", "Player 2", "Player 3", "Player 4", "Player 5", "Player 6", "Player 7", "Player 8", "Player 9", "Player 10")
            If WorksheetFunction.CountIf(Sheets(ws).Range("D:R"), Target.Value) > 1 Then
               Target.Interior.ColorIndex = 3
               Target.Font.ColorIndex = 2
               Exit For
            Else
               Target.Interior.ColorIndex = xlNone
               Target.Font.ColorIndex = xlAutomatic
            End If
         Next
      Else
         Target.Interior.ColorIndex = xlNone
         Target.Font.ColorIndex = xlAutomatic
      End If
   End If
   Application.EnableEvents = True
End If

End Sub

For detail, refer to the attached workbook.

Please find the attached and see if this works now.
I have entered the described company name in Player1 and Player5 sheets and it's highlighting the company name on Player 5 sheet.

Which conditional formatting you are talking about? Is it one which is applied through the conditional formatting rule or one which is applied by the code in the cells with the duplicate values.
Always attach the workbook in the question when you say it is not producing the desired output.

Can Company Name and Name of DM be the same? If that is the case, this approach will not work.

Not sure why the blank cells were highlighted with red but when I deleted them the red color disappeared.
Also tweaked the code in case if you input the numbers for the company name which is not likely to be case.

You're welcome.

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