Is it the inner handle that no longer works ? This is on the S60
https://youtu.be/Jd7JNhUrD1g There are several part no so may want to look up on Ebay for a used one from an XC90. I doubt Volvo would sell the plastic part separately, and the whole door card may be quite expensive. However it can be 'patched' to work, using a metal clamp or alike