Explanation
Setting the Maximum Value Type to Threshold Amount is available only for Taxes (not Additional Earnings or Benefits). If the Maximum Value Type is set to Threshold Amount, then the threshold of each tier drives the tiered calculations. The application applies all tiers to the default assignment, as appropriate, regardless of the tier assigned as a default.
References:
https://docs.oracle.com/cloud/latest/pbcs_common/EPBCA/wf_about_maximum_value_type_110x00c2886b.htm