Circular reference

UnitA.pas

unit UnitA;

interface

uses
    TUnitB;

type
    TUnitARecord = record
        ...
        ...
    end;

    TUnitA = Class
        ...
        private
            FExemploB: TUnitB;
        ...
        ...
        ...
    End;

implementation

uses
    UnitADAO;
    ...
    ...
end.

UnitADAO.pas

unit UnitADAO;

interface

uses
    UnitA;
type
    TUnitADAO = Class
        function foo(): TUnitARecord;
        function bar(): TUnitARecord;
        ...
        ...
    End;

implementation

uses
    UnitB;
    
    ...
    ...
end.

UnitB.pas

unit UnitB;

interface

uses
    TUnitA;

type
    TUnitBRecord = record
        ...
        ...
    end;

    TUnitB = Class
        ...
        private
            FExemploA: TUnitA;
        ...
        ...
        ...
    End;

implementation
    UnitBDAO;
    ...
    ...
end.

UnitBDAO.pas

unit UnitBDAO;

interface

uses
    UnitB;
type
    TUnitBDAO = Class
        function foo(): TUnitBRecord;
        function bar(): TUnitBRecord;
        ...
        ...
    End;

implementation

uses
    UnitA;
    
    ...
    ...
end.