Searching for Window ope/close rail

Hello there. I believe you are referring to the track slide piece on the window hinge. I am afraid these parts are not meant to be replaced individually, and when they break it's a sure sign the entire window hinge should be replaced. See our 10" 36-004-10. Review the dimensions below and see if you think this hinge set matches what you need.

DImensions for 36-004-10

Detailed view of the slider for 36-004-10