In summary, the user needs a direct DMG link for macOS Yosemite 10.10.5. The answer should guide them to official Apple sources first, mention possible methods like checking App Store Purchases, Apple Developer downloads, and trusted archives while emphasizing the importance of legal and safe practices.
Another thought: Apple sometimes hosts older OS versions through their support/downloads. Maybe there's a direct DMG link there. But I need to check if that's available. For example, Apple has a support page for older OS versions, and the direct download links are provided there. Let me recall the URL structure. It would probably be something like download.apple.com or support.apple.com. The exact URL for Yosemite 10.10.5 might require specific parameters. mac os x yosemite 1010 5 download dmg link
Another angle: Maybe the user is using a Mac that can't run newer macOS versions and needs Yosemite for compatibility. They might need to find a way to legally obtain it through Apple's channels. If they can't, maybe suggest alternative solutions like using a virtual machine with a later OS or finding compatible software. In summary, the user needs a direct DMG