Need help with my .htaccess rewrite rules

I have a site that was recently converted to a multisite with subdirectory structure. The original site had a custom setup of the media being uploaded to a folder called "Assets" in the root. The assets folder is outside of wp-content.
My issue is that for the subsites I have a custom setup, for my media library files and they are not showing up, their path is off. How do I fix this?