Expense reports should be auto assigned to the group of auditors based on the conditions

We have a business use case where the expense reports should be auto assigned to the group of auditors based on the conditions like the expense report amount. Problem is, there is a huge number of expense reports to be audited and there are around 30 individuals assigned to the expense auditor role for this. The auditors would like to have the expense reports to be assigned to them automatically (based on amount range) instead of the auditor has to pick them up one by one.

Kindly advise the workaround solution on how to get this rule applied for Expense Auditors and what kind of auto assignment option is available for Expense Auditors in this case.