What do you mean by Customized DFF?

If you want to list all custom context that is created on a specific DFF you can run this query to get the result:

SELECT FAPT.APPLICATION_NAME,
FDFC.DESCRIPTIVE_FLEXFIELD_NAME,
FDFC.DESCRIPTIVE_FLEX_CONTEXT_CODE,
FDFC.ENABLED_FLAG,
FDFC.GLOBAL_FLAG,
FDFC.DESCRIPTION,
FDFC.DESCRIPTIVE_FLEX_CONTEXT_NAME
FROM FND_DESCR_FLEX_CONTEXTS_VL FDFC, FND_USER FU, FND_APPLICATION_TL FAPT
WHERE FAPT.APPLICATION_NAME = :P_APPLICATION_NAME
AND FDFC.DESCRIPTIVE_FLEXFIELD_NAME LIKE :P_DFF_NAME
AND FDFC.CREATED_BY = FU.USER_ID
AND FDFC.APPLICATION_ID = FAPT.APPLICATION_ID
AND FAPT.LANGUAGE = 'US'
AND ( FU.USER_NAME NOT LIKE '%ORACLE%'
AND FU.USER_NAME NOT LIKE '%AUTOINSTALL%'
AND FU.USER_NAME NOT LIKE '%INITIAL SETUP%');

P_APPLICATION_NAME : Is your application name

P_DFF_NAME : Is your Descriptive flexfield name. It’s not the title which is available on DFF screen, but you can find the column name “DESCRIPTIVE_FLEXFIELD_NAME” from help -> diagnostic -> examine.

Note: We have excluded three users because Oracle seeded DFF contexts are created by these users above, thus, we can get only the custom ones.