Unfortunately, the planned type of use is not entirely clear.
If the idea is that both computers can use the display without switching/plugging in (i.e. actually KVM functionality), then no, this is not possible.
The hub only has one "computer"/host port, i.e. only one computer can be connected, which outputs a signal to the display and uses other connected devices.

If a second computer is connected to the hub in addition to the one on the host port, then the "host" could communicate with the second computer, e.g. as a network via Thunderbolt. Whether this actually works is unfortunately dependent on too many variables. It should work with the Windows computer on the host port and the Mac on one of the slave/device ports. In this case, however, the Mac can only communicate with the Windows computer but cannot use any of the other components (e.g. cannot output anything to the display).

At the same time? No.