Searching for guider for casement windows

This looks like a slider on a hinge assembly. These are unfortunately not sold separately. If yours is broken then you will need an all new hinge set entirely.

I'd be happy to help, but I would need a clear picture of the hinge in question as unobscured by the window as possible. I'd also like you to tell me the length of the track that it uses to mount to the sill. That information will allow me to determine if we have a good match in our inventory.