Here is the short/simple function in postgresql 9.6.
CREATE OR REPLACE FUNCTION public.sec_select_labor_data(
)
RETURNS SETOF acct_nbr_lst
LANGUAGE 'plpgsql'
AS $BODY$
Declare
v_cnt numeric;
sec_role varchar(20);
v_netid varchar(30);
begin
RETURN QUERY Select acct_nbr from kdw_acct_security where lower(netid) = CURRENT_USER;
end;
$BODY$;