If you mean having multiple mouse cursors on-screen at once, such as to allow two people to use a system simultaneously, or to use a separate mouse and cursor for each screen, there is third-party software for that. I haven't messed with it much though, so I couldn't tell you how well it works.
TeamPlayer was the best-known option for a while, but it was apparently discontinued some time back. There are a couple free versions of the software floating around that still work though. It sounds like the two mice can't be clicked simultaneously with that solution, though that might not be much of an issue depending on your use-case.
MouseMux is a newer utility still in beta that appears to provide similar functionality, and the beta version can be used for free without any time limit (for non-commercial use). It sounds like it might offer some improvements over TeamPlayer with its "multiplex" mode, though it is still in beta, and might potentially have issues with some software.