No a keďže sa Ti tam u viacerých Case x opakujú tie isté delenia pre Case y, môžeš to spriahnuť a výsledný kód sa zjednoduší cca na polovicu:

Private Sub ComboBox30_Change()
Dim x As Byte
Dim y As Byte

On Error Resume Next
x = ComboBox2.ListIndex
y = ComboBox30.ListIndex
On Error GoTo 0

Select Case x
    Case 0
        Select Case y
            Case 0
                ComboBox58.ListFillRange = ""
        End Select
    Case 1, 5
        Select Case y
            Case 1 To 10
                ComboBox58.ListFillRange = "vera"
            Case 11 To 22
                ComboBox58.ListFillRange = "verb"
        End Select
    Case 2, 6
        Select Case y
            Case 1 To 5
                ComboBox58.ListFillRange = ""
            Case 6 To 7
                ComboBox58.ListFillRange = "vera"
            Case 8 To 22
                ComboBox58.ListFillRange = "verb"
        End Select
    Case 3, 7
        Select Case y
            Case 1 To 7
                ComboBox58.ListFillRange = "vera"
            Case 8 To 22
                ComboBox58.ListFillRange = "verb"
        End Select
    Case 4, 8
        Select Case y
            Case 1 To 5
                ComboBox58.ListFillRange = "verb"
            Case 6 To 7
                ComboBox58.ListFillRange = "vera"
            Case 8 To 22
                ComboBox58.ListFillRange = "verb"
        End Select
End Select
End Sub