How to split column data into rows in Oracle

SELECT REGEXP_SUBSTR (:P2_SELECTED_NODES,

                          '[^:]+',

                          1,

                          ROWNUM)

              ID

      FROM DUAL

CONNECT BY LEVEL <= LENGTH (REGEXP_REPLACE (:P2_SELECTED_NODES, '[^:]+')) + 1;

Input: 1:2:3:4

Output: 

1

2

3

4