Wheels from Volvo XC60 on Volvo V90: compatible?

No, the centre bore is too small

Same 5x108 PCD, but the centre bore of the wheels from Volvo XC60 (63.4 mm) is smaller than the hub of Volvo V90 (65.1 mm): they will not fit without being re-bored by a professional.

Volvo XC602008–2017Volvo V901996–1998
PCD5x1085x108
Centre bore63.4 mm65.1 mm
ThreadM14x1.50Ecrous - 12x1.50
Original wheels 7.5Jx17 ET55 ≈6.5Jx15 ET43
≈7Jx17 ET47

≈: width estimated from the original tyre size.

Before fitting the wheels

An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Volvo V90 (Ecrous - 12x1.50), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.

And the other way round: wheels from Volvo V90 on Volvo XC60?