DFF Doesn't show the values on the Assignment Page

Summary:

Hi Expert,

I created a DFF on PER_ASG_DF and below query and tried to see this value on the page, but I can't see this information.

Can someone tell me whats the issue is?

SELECT  distinct
ffv.flex_value

FROM fnd_flex_value_sets ffvs ,
fnd_flex_values ffv ,
fnd_flex_values_tl ffvt,
HR_ALL_POSITIONS_F hapf

WHERE
ffvs.flex_value_set_id = ffv.flex_value_set_id
and ffv.flex_value_id = ffvt.flex_value_id
AND ffvt.language = USERENV('LANG')
and ffvs.flex_value_set_name like 'S_Cost_Center'
and to_char(ffvt.FLEX_VALUE_ID) = to_char(hapf.COST_CENTER)