Hello pylauzier,

Welcome to the Forum!

Here is your converted macro. If you have more text boxes, just add then to the srchArray. All the matching results are listed starting in cell B3.
Private Sub CommandButton1_Click()

    Dim c3 As Range
    Dim DstRange As Range
    Dim f As String
    Dim Item As Variant
    Dim R As Long
    Dim srchArray As Variant
    Dim SrchRng3 As Range
    
        Set DstRange = ActiveSheet.Range("B3")
  
        Set SrchRng3 = ActiveSheet.Range("H1", ActiveSheet.Range("H100").End(xlUp))
        
        srchArray = Array(TextBox1.Text, TextBox2.Text, TextBox3.Text)
    

          For Each Item In srchArray
            Set c3 = SrchRng3.Find(Item, , xlValues, xlWhole, xlByRows, xlNext, False)
            If Not c3 Is Nothing Then
               f = c3.Address
                 Do While Not c3 Is Nothing
                   DstRange.Offset(R, 0) = c3.Value
                   R = R + 1
                   Set c3 = SrchRng3.FindNext(c3)
                   If c3.Address = f Then Exit Do
                 Loop
          Next Item

End Sub