Need Help with Absence validation formula FORMULA TYPE: Global Absence Entry Validation

Hi Experts

My requirement is I have restrict the number leave to 10 per child birth (which can be taken separately)

Can you kindly help me where to include the child date of birth validation here . here its checking for leaves taken in a year but I have check for each child birth through its date

I am new to fast formulas:

FORMULA TYPE: Global Absence Entry Validation

DEFAULT FOR IV_START_DATE IS '4712/12/31 00:00:00' (date)
DEFAULT FOR IV_END_DATE IS '4712/12/31 00:00:00' (date)

DEFAULT FOR IV_TOTALDURATION IS 0
DEFAULT_DATA_VALUE for ANC_PER_ABS_ENTRS_ABSENCE_ENTRY_ID_ARR is 0