I would do something like this:
Sub First()
For cnt = 1 To 5
k = k + 1
If Second(k) Then
Exit Sub
End If
Debug.Print "k--" & k
Next cnt
End Sub
' Change this to a Function instead of Sub.
' Return True when we should exit both functions.
Function Second(ByVal u As Single) as Boolean
If u = 3 Then
Second = True
Exit Function 'Exit Second procedure
End If
Debug.Print "u--" & u
Second = False ' This line is not necessary in VBA
' ...because False would be the default return value anyway.
' ...(This is not the case in future VB versions...)
End Function