define APC combination to return in kin and kin2sex.
output_period_cohort_combination(
output_cohort = NULL,
output_period = NULL,
age = NULL,
years_data = NULL
)data.frame with years and ages to filter in kin and kin_2sex functions.
Because returning all period and cohort data from a huge time-series would be hard memory consuming,
this function is an auxiliary one to deal with selection from inputs output_cohort and output_period.