Exp category based approvals

We have below requirement from the client. Currently we are having the hierarchy-based approval in the Oracle Fusion Expenses but now client want to use the expense category based approvals for few specific expense categories without changing the hierarchy-based approval in expenses. If we configure category based approvals, can we use two different expense categories in one expense report? in this case how the approvals will be triggered as there are two different (hierarchy-based approval and category based) approvals in one expense report.