Oracle 11g Release 2

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE USER_DETAILS
(
  EMPNO VARCHAR2(20 BYTE),
  ENAME VARCHAR2(40 BYTE)
);
CREATE TABLE GROUP_DETAILS
(
  GROUPNO VARCHAR2(20 BYTE),
  GROUPNAME VARCHAR2(40 BYTE)
);
CREATE TABLE MENU_DETAILS
(
  MENUNO VARCHAR2(20 BYTE),
  MENUNAME VARCHAR2(40 BYTE),
  PARENT VARCHAR2(10 BYTE)
);
CREATE TABLE ASSIGN_MENU_DETAILS
(
  GROUPNO VARCHAR2(20 BYTE),
  MENUNO VARCHAR2(20 BYTE)
);
CREATE TABLE USER_GROUP_DETAILS
(
  EMPNO VARCHAR2(20 BYTE),
  GROUPNO VARCHAR2(20 BYTE)
);
INSERT INTO USER_DETAILS (EMPNO, ENAME)
VALUES
('EMP-0001', 'John');
1 rows affected

INSERT INTO USER_DETAILS (EMPNO, ENAME)
VALUES
('EMP-0002', 'Jack');
1 rows affected

INSERT INTO GROUP_DETAILS (GROUPNO, GROUPNAME)
VALUES
('GROUP-0001', 'GROUP-1');
1 rows affected

INSERT INTO GROUP_DETAILS (GROUPNO, GROUPNAME)
VALUES
('GROUP-0002', 'GROUP-2');
1 rows affected

INSERT INTO MENU_DETAILS (MENUNO, MENUNAME, PARENT)
VALUES
('1001', 'User Details', NULL);
1 rows affected

INSERT INTO MENU_DETAILS (MENUNO, MENUNAME, PARENT)
VALUES
('1002', 'Add User', '1001');
1 rows affected

INSERT INTO MENU_DETAILS (MENUNO, MENUNAME, PARENT)
VALUES
('1003', 'Department Details', NULL);
1 rows affected

INSERT INTO MENU_DETAILS (MENUNO, MENUNAME, PARENT)
VALUES
('1004', 'Add Department', '1003');
1 rows affected

INSERT INTO ASSIGN_MENU_DETAILS (GROUPNO, MENUNO)
VALUES
('GROUP-0001', '1001');
1 rows affected

INSERT INTO ASSIGN_MENU_DETAILS (GROUPNO, MENUNO)
VALUES
('GROUP-0001', '1004');
1 rows affected

INSERT INTO USER_GROUP_DETAILS (EMPNO, GROUPNO)
VALUES
('EMP-0001', 'GROUP-0001');
1 rows affected

INSERT INTO USER_GROUP_DETAILS (EMPNO, GROUPNO)
VALUES
('EMP-0001', 'GROUP-0002');
1 rows affected

WITH 
CTE (MENUNO,
     MENUNAME,
     PARENT) AS
(
SELECT M.MENUNO,
       M.MENUNAME,
       M.PARENT
       FROM USER_DETAILS U
            INNER JOIN USER_GROUP_DETAILS UG
                       ON UG.EMPNO = U.EMPNO
            INNER JOIN ASSIGN_MENU_DETAILS AM
                       ON AM.GROUPNO = UG.GROUPNO
            INNER JOIN MENU_DETAILS M
                       ON M.MENUNO = AM.MENUNO
       WHERE U.EMPNO = 'EMP-0001'
UNION ALL
SELECT M.MENUNO,
       M.MENUNAME,
       M.PARENT
       FROM MENU_DETAILS M
            INNER JOIN CTE C
                       ON C.PARENT = M.MENUNO
)
SELECT DISTINCT
       MENUNO,
       MENUNAME
       FROM CTE;


MENUNO
MENUNAME


1004
Add Department

1003
Department Details

1001
User Details