Although they are vastly different in approach, there is some overlap in capabilities of Pega 7 and TIBCO Business Events.
TIBCO Business Events is their general purpose event and business rules platform. It has several paradigms for evaluating event state, such as state machine modeling, declarative conditional expressions, process orchestration and some streaming calculations. Most of them have a large amount of textual coding in their Business Event language with some visual elements. You create inbound and outbound connections to receive and send XML messages and other content depending on the connection type. Business rules in the platform fire and call your scripts or imported Java libraries. Although it has a process orchestration metaphor, It does not handle BPM and workflow, and is complicated to use for streaming analytics. It also provides no functional user interface design capability.
Pega 7 has a world class rules engine at the core, market leading BPM and case management, and the Decision Hub handles big data as well as streaming data. All in one no-coding visual design environment and single run-time platform, including everything enterprise-scale applications need from UI to integration.
If you can describe the use case you have in mind for Business Events, I can provide some insight as the Pega platform approach to the use case.