SELECT ID, TREE_NAME, PARENT_ID  FROM MY_TREE; 
1	a	NULL
2	b	NULL
3	c	1
4	d	1
5	e	4

 SELECT ID, TAB_TREE_ID, TAB_NAME FROM MY_TABLE;
1	3	aaa
2	5	bbb
3	5	ccc
4	5	ddd
5	5	eee
6	5	fff

 SELECT ???;
1	3	aaa	3
1	3	aaa	1

2	5	bbb	5
2	5	bbb	4
2	5	bbb	1

3	5	ccc	5
3	5	ccc	4
3	5	ccc	1

и т.д.

 SELECT MY_TABLE.*, TREE.ID
FROM MY_TABLE, MY_TREE
START WITH MY_TREE.ID = MY_TABLE.TAB_TREE_ID
CONNECT BY PRIOR MY_TREE.PARENT_ID = MY_TREE.ID

SELECT MY_TABLE.*, TREE.ID
FROM MY_TABLE, MY_TREE
START WITH MY_TREE.ID = MY_TABLE.TAB_TREE_ID
CONNECT BY PRIOR MY_TREE.PARENT_ID = MY_TREE.ID

SELECT	MY_TABLE.*, ttt.ID
FROM		MY_TABLE
	,	(SELECT	MY_TREE.ID		ID
		,	CONNECT_BY_ROOT ID	CONNECT_ID
		FROM	MY_TREE
		CONNECT BY PRIOR MY_TREE.PARENT_ID = MY_TREE.ID
		) ttt
WHERE	MY_TREE.ID = ttt.CONNECT_ID

SELECT	MY_TABLE.*, ttt.ID
FROM		MY_TABLE
	,	(SELECT	MY_TREE.ID		ID
		,	CONNECT_BY_ROOT ID	CONNECT_ID
		FROM	MY_TREE
		CONNECT BY PRIOR MY_TREE.PARENT_ID = MY_TREE.ID
		) ttt
WHERE	MY_TABLE.ID = ttt.CONNECT_ID