SecuritySpy 
Multi-camera CCTV software for the Mac
Features — Synchronised multi-camera playback
SecuritySpy's Browser feature allows you to easily play back, export and manage captured footage.
The Browser allows synchronised playback of multiple cameras, and has a timeline that provides a visual representation of the recorded footage for your cameras throughout each day. Here is an example with four cameras selected:
The Browser can show a list of files, or a list of events (detected motion, or AI-detected humans or vehicles). It also has an Advanced Search function, whereby you can search the captured footage for specific events in specific locations of each video feed:
Other features of the Browser include movie export, bookmarks (to mark specific times in the timeline for future reference), file tagging, and digital zoom.
Captured footage can also be played back via SecuritySpy's web interface and iOS/tvOS app.