Possible to create an aux send?

Hello! In a situation where two instrument input signals are processed independently in their own effects chains, is it possible to have a controllable amount of each signal go to one effects send to be processed by an external effects device (i.e. the desire is to have the effect wetter on one signal chain than the other)? It’s basically the equivalent of using an aux send on a mixer, with a different send amount on each channel.