Usb Mic on two devices?

I do not want to switchen or use two devices with the PS4 and the PC. First I thought of a mixer, but since the mic does not send the sound in analogue, that is not possible.

Is there a switch or a hub to PS4 and PC at the same time AND even without a PC to use the micro and the headphones?

I do not see a chance. The only thing that exists, that is a USB switch, because you can select with a button, which PC can get the devices.

Offer has poorly translated German, but so what is it:

https://www.amazon.de/...B01N6GD9JO

Where are the headphones plugged in?

Certainly a Y adapter can help. Today, there are switches for all sorts of connections that allow you to use a device wherever you need it.

On the PS4 controller or on the PC (headphone jack)

You can bring the two outputs to the headphones via an audio mixer. Also look for it on Ebay or Amazon.