Passing variable from child theme function to parent theme filter

I’m not exactly sure what you’re trying to accomplish but this won’t work because your trying to use or call the function that is declared in the parent theme instead of replacing it with a new function. I’m not sure if replacing a function in the child theme would work either. Maybe someone else can help answer that.

The function map_thumbnail() that you’re trying to call in the child theme, is actually being used by the add_filter() function right above it to modify the existing function post_thumbnail_html().

Additionally, even if it would work, you only passed one paramater (‘#0099dd’) in your attempt to call the function, and it appears to be out of order.