Directly attributable cost in business combination?

WHAT IS DIRECTLY ATTRIBUTABLE COSTS

A business combination is defined in Appendix of AASB 3 as "the bringing together of separate entities or business into one reporting entity". Exposure Draft ED 139: Proposed Amendments to AASB 3 Business Combinations proposes changing (at the time of writing) this definition slightly to "a transaction r other event in which an acquirer obtains control of one or more business.