Default DFF value based on another field

Summary:

Default DFFF value based on another field

Content (please ensure you mask any confidential information):

Created DFF in requisition line for cost center

In the dff value we need , system automatically populate the cost center of Requestor from default employee account string

what should be the default sql query

it is not defaulting the correct cost string from employee

select gcc.segment3 COST_CENTER
FROM
per_all_assignments_m paa,
poR_requisition_lines_all prl,
gl_code_combinations gcc
WHERE 1 = 1
and paa.person_id = prl.requestEr_id
AND paa.default_code_comb_id = gcc.code_combination_id
--and requester_id = {PARAMETER.RequesterId}