I'm afraid I don't think it works like that, although the specifics of xG algorithms that stats companies use are generally closely guarded secrets, they often talk about how it works in loose terms.

xG is usually produced by a huge predictive model which takes in a combo basically every possible data point you can imagine to do with a football match.

Opta talks about their model being fed by things like historic data for the ball position, limb positions, the quality of passing building up to a shot (some models talk about every pass from when the ball was out of play), the quality of the keeper in front and all sorts of other stuff they don't let on about.

Given all that I'm not sure it's possible to meaningfully normalise a player's xG because it's a product of other players on a pitch. So I think it's fair to conclude that a poorly performing team will very likely be negatively impacting an individual's xG.