I am not quite sure what you mean by that.
You want to have two sink pads for the same element?
I am not sure if that works, @yuweiw can answer this better.
if this is your pipeline:
sinkpadprobe → element → srcpadprobe
and you need two sink pad probes, add a queue or something
sinkpadprobe → element → sinkpadprobe → queue → srcpadprobe.
Although I hope someone provides a much better solution that this.