One Website for Remarketing for another website

I don't know how to structure my question.

I sell product "A" on website X.

And I want to use another website Y which is a review website to do remarketing for people who visited website X but haven't purchased.

Can it be done by Google Ads or FB Ads ?

From what I'm understanding, you want to target X with the Y visitors? or you to target Y with X traffic?
no matter the order, you can do this in 2 ways:

1. Implement Google Ads Tag on both sites and create a remarketing list with the traffic from site Y and create a campaign in which you send traffic to X.
2. 2 separates accounts, under a MCC and share between accounts the rmk lists that you want to use.

same for facebook