1. A transaction allocation system, comprising: a processor; and memory storing instructions that, when executed by the processor, cause the processor to: access a first allocation rule associated with one of a plurality of business objects represented by a hierarchical data structure; execute a first query on transaction data using a query engine, the first query being based on the first allocation rule, the transaction data characterizing one or more transactions; access a second allocation rule associated with another of the plurality of business objects represented by the hierarchical data structure; and execute a second query on a subset of the transaction data using the query engine, the second query being based on the second allocation rule and identifying a business object for determining allocation of at least one of the one or more transactions; and generate transaction allocation output based on results of the first and second queries.