Using the Shell API function SHBrowseForFolder

uses ShellAPI, ShlObj;
 
procedure TForm1.Button1Click(Sender: TObject);
var
  TitleName : string;
  lpItemID : PItemIDList;
  BrowseInfo : TBrowseInfo;
  DisplayName : array[0..MAX_PATH] of char;
  TempPath : array[0..MAX_PATH] of char;
begin
  FillChar(BrowseInfo, sizeof(TBrowseInfo), #0);
  BrowseInfo.hwndOwner := Form1.Handle;
  BrowseInfo.pszDisplayName := @DisplayName;
  TitleName := 'Please specify a directory';
  BrowseInfo.lpszTitle := PChar(TitleName);
  BrowseInfo.ulFlags := BIF_RETURNONLYFSDIRS;
  lpItemID := SHBrowseForFolder(BrowseInfo);
  if lpItemId  nil then begin
    SHGetPathFromIDList(lpItemID, TempPath);
    ShowMessage(TempPath);
    GlobalFreePtr(lpItemID);
  end;
end;