Advanced Filter
It is possible to perform an advanced filter with Soen’s Ralph code, remove the accent from the word with the Extendoffice code and ignore lowercase or uppercase by capitalizing the tuple with Ucase()
The filter is performed in a form named Userform1, a text box named Textbox1 and a list named Listbox1.

Code
Private Sub Textbox1_Change()
    'https://stackoverflow.com/a/42880069/7690982
    Dim i As Long
    Dim arrList As Variant
    Dim ws As Worksheet
    Set ws = ThisWorkbook.Worksheets("Nome da Planilha")
    Me.ListBox1.Clear
    If ws.Range("A" & ws.Rows.Count).End(xlUp).Row > 1 And Trim(Me.TextBox1.Value) <> vbNullString Then
        arrList = ws.Range("A1:A" & ws.Range("A" & ws.Rows.Count).End(xlUp).Row).Value2
        For i = LBound(arrList) To UBound(arrList)
            If InStr(1, UCase(StripAccent(CStr(arrList(i, 1)))), UCase(StripAccent(Trim(Me.TextBox1.Value))), vbTextCompare) Then
                Me.ListBox1.AddItem arrList(i, 1)
            End If
        Next i
    End If
    If Me.ListBox1.ListCount = 1 Then Me.ListBox1.Selected(0) = True
End Sub
Public Function StripAccent(thestring As String)
    'https://www.extendoffice.com/documents/excel/707-excel-replace-accented-characters.html
    Dim A As String * 1
    Dim B As String * 1
    Dim i As Integer
    Const AccChars = "ŠŽšžŸÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖÙÚÛÜÝàáâãäåçèéêëìíîïðñòóôõöùúûüýÿ"
    Const RegChars = "SZszYAAAAAACEEEEIIIIDNOOOOOUUUUYaaaaaaceeeeiiiidnooooouuuuyy"
    For i = 1 To Len(AccChars)
        A = Mid(AccChars, i, 1)
        B = Mid(RegChars, i, 1)
        thestring = Replace(thestring, A, B)
    Next
    StripAccent = thestring
End Function
Upshot
The letter is typed in Textbox1 and the filter is performed as shown below:


EDIT:
Multiselect
There are three options of Multiselect:
- ListBox.MultiSelect = 1: Select only one element.
- ListBox.MultiSelect = 2: Click the item or press the space bar to select multiple items
- ListBox.MultiSelect = 3: Press Shift and Ctrl to select multiple items
Code
Then the following code is used to change the setup settings when starting the form.
Private Sub UserForm_Initialize()
    'Entre outros códigos de inicialização
    Me.ListBox1.MultiSelect = 1
End Sub
Filter Dynamic Table Button
A button CommandButton can be added and after the data is chosen, these will be filtered in the Dynamic Table.
Code
The Function IsInArray() of the Jimmypena of the Soen is used.
Private Sub CommandButton1_Click()
    Dim i As Long, j As Long
    Dim PvtTbl      As PivotTable
    Dim PvtItm      As PivotItem
    Dim ws As Worksheet
    Dim arr() As Variant
    On Error GoTo Sair
    With Application
        .EnableEvents = False
        .ScreenUpdating = False
        .Calculation = xlCalculationManual
    End With
    Set ws = ThisWorkbook.Sheets("Nome da Planilha")
    Set PvtTbl = ws.PivotTables("Tabela dinâmica1")
    PvtTbl.ManualUpdate = True
    For i = 0 To ListBox1.ListCount - 1
        If Me.ListBox1.Selected(i) = True Then
            ReDim Preserve arr(j)
            arr(j) = Me.ListBox1.List(i)
            j = j + 1
        End If
    Next i
    With PvtTbl.PivotFields("campo")
        .ClearAllFilters
        For Each PvtItm In .PivotItems
            If IsInArray(PvtItm.Name, arr) = True Then
                PvtItm.Visible = True
            Else
                PvtItm.Visible = False
            End If
        Next PvtItm
    End With
Sair:
    Set PvtTbl = ws.PivotTables("Tabela dinâmica1")
    PvtTbl.ManualUpdate = False
    Debug.Print Err.Description
    On Error GoTo 0
    With Application
        .EnableEvents = True
        .ScreenUpdating = True
        .Calculation = xlCalculationAutomatic
    End With
End Sub
Function IsInArray(stringToBeFound As String, arr As Variant) As Boolean
'https://stackoverflow.com/a/10952705/7690982
  IsInArray = (UBound(Filter(arr, stringToBeFound)) > -1)
End Function
							
							
						 
Enter the code in this question. Welcome(a). Please do the [tour], then read How we should format questions and answers? and create a [mcve] for the question. Because the question is too wide and when you are more specific, there are more chances of your question being answered correctly.
– danieltakeshi
@danieltakeshi I believe I have simplified the question... Your suggestions are very welcome I thank you already.
– André Machado