if (p is TCheckedComboBox) then begin
                                if (p as TCheckedComboBox).EmptyValue <> '' then
                                  FLD.GetCheckComboBoxValue([Mask+Copy(p.Name,3,Length(p.Name))],(p as TCheckedComboBox).EmptyValue);
                            end;

[Error]  Undeclared identifier: 'GetCheckComboBoxValue'

uses
...
  function GetCheckComboBoxValue(ctrl: TCheckedComboBox): string;
...
implementation

procedure FillFldByCompontents(aForm: TForm; FLD: TVars; Mask:string);
var
  i,j : Integer;
  p : TComponent;

begin
  with aForm do
    for i := 0 to ComponentCount-1 do begin
      p := Components[i];
      if (p is TCheckedComboBox) then begin
      if (p as TCheckedComboBox).EmptyValue <> '' then
      FLD.GetCheckComboBoxValue([Mask+Copy(p.Name,3,Length(p.Name))],(p as TCheckedComboBox).EmptyValue);
      end;
    end;
end;

FLD.GetCheckComboBoxValue // Что за класс имеет переменная FLD? И есть ли у неё public метод GetCheckComboBoxValue

unit BrsDevInfra_FUtils;

interface
uses
  {$IFDEF UNICODE}
  Variants,
  {$ENDIF}
  API_UFuncApp,
  RxLookup,
  API_uQIService,
  API_UEdAccOrClientTools,
  SYS_UVAR,
  SYS_uStr,
  SYS_UQIntAbstr,
  SYS_uCRC32,
  SYS_uMsg,
  SYSLIB_UQIServ,
  SYS_uSessMan,
  API_FDBPassword,
  CheckCombo,
  EXP_uDlgDBPick,
  Windows, Messages, SysUtils, OraScript, Ora, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, DB, mask, CurrEdit, ToolEdit, ExtCtrls, CheckLst, TB2Item,
  frxVariables,
  BrsApi_Odac,RxDBComb;

  procedure FillFldByCompontents(aForm: TForm; FLD: TVars; Mask:string);
  procedure FillCompontentsByFld(aForm: TForm; FLD: TVars; Mask:string);
  procedure Str2Params(const aStr, aSectName : string; out aParams : TVars);
  function Params2Str(const varsFld : TVars; SectName: string = ''): String;
  procedure SetupStatusModesButton(
                           App : TFuncApp;
                           tbSubModes : TTBSubmenuItem;
                           tbiModeClick : TNotifyEvent;
                           aRef : string);
  function nvl(aValue: string; aDefault: string): string;
  function CheckControl(p: TComponent; isWarning: boolean):boolean;
  procedure SetDefaultComboValues(aForm: TForm;aFormTuneKind:integer;FLD: TVars);
  function GetCheckComboBoxValue(ctrl: TCheckedComboBox): string;

implementation

function CheckControl(p: TComponent; isWarning: boolean):boolean;

      FLD.GetCheckComboBoxValue([Mask+Copy(p.Name,3,Length(p.Name))],(p as TCheckedComboBox).EmptyValue);

    if (p is TCheckedComboBox) then
         begin
            GetCheckComboBoxValue( p as TCheckedComboBox );
         end;

                            if (p is TComboBox) then begin
                               if (p as TComboBox).Text <> '' then
                                 FLD.PutVal([Mask+Copy(p.Name,3,Length(p.Name))],(p as TComboBox).Text);
                            end

FLD.GetCheckComboBoxValue

BrsDevInfra_FUtils.GetCheckComboBoxValue

                            if (p is TComboBox) then begin
                               if (p as TComboBox).Text <> '' then
                                 FLD.PutVal([Mask+Copy(p.Name,3,Length(p.Name))],(p as TComboBox).Text);
                            end

            
 var StrComboValue:string;
 // .... 
 if (p is TCheckComboBox) then begin
    begin
        StrComboValue:=GetCheckComboBoxValue(p as TCheckComboBox);
        if  StrComboValue<> '' then   // 
            FLD.PutVal([Mask+Copy(p.Name,3,Length(p.Name))], StrComboValue);
    end

   // засунем в FLD: TVars  все значения, собранные с формы
   for i:=0 to Pred(AForm.ComponentCount) do
        begin
            //........
           if (Components[i] is .....) then
               begin
                   StringForPut:= GetControlXXXXValue (Components[i] as .....);
                   FLD.PutVal( _Name_, StringForPut);
               end;
            //.... 
        end;

   // теперь нам нужно где-то отобразить то, что мы насобирали
   for i:=0 to Pred(FLD.Count) do
        Memo.Lines.Add(FLD.GetValue(_NAME_));

procedure TfrmEditDevice.InitCheckComboBox(App: TFuncApp; ctrl: TCheckedComboBox; aSql: string; aStr: string; const ParamArr: array of const);
var s: string;
    i: integer;
    bool: boolean;
    que: TOraQuery;
begin
  que := GetQueryBySQL(aSql, ParamArr);
  try
    with ctrl do begin
      Clear;
      with que do begin
        First;
        while not Eof do begin
          s := '';
          if (que.FieldCount = 6) then
            if Fields[2].asString <> '' then
              s := '['+Fields[2].asString+'] ';
          Items.Add(Fields[0].asString+' - '+s+Fields[1].asString);
          Next;
        end;
      end;
      for i := 1 to Items.Count do begin
        s := Trim(GetWord(1,Items[i-1],['-']));
        bool := IsWordPresent(s,aStr,[',']);
        Checked[i-1] := bool;
      end;
    end;
  finally
    que.Close;
    App.QI.FreeQuery(que);
  end;
end;
...
InitCheckComboBox(aApp, ccbDEV_PAYSYSTEM, shDEV_PAYSYSTEM.SQL.Text, GetCheckComboBoxValue(ccbDEV_PAYSYSTEM), []);
...

                            if (p is TCheckedComboBox) then
                            StrComboValue:=GetCheckComboBoxValue(p as TCheckedComboBox);
                            (p as TCheckedComboBox).EmptyValue := FLD.GetValDef([StrComboValue],'')