For filtering parameters, prepend \ to special characters + - & | ! ( ) { } [ ] ^ ' " ~ * ? : \ and space according to Amazon Cloud Drive API documentation, and encode space as %20 instead of + to avoid mistaking space as plus sign in filtering parameter.
Amazon Cloud Drive API documentation on escaping special characters of filtering parameters:
https://developer.amazon.com/public/apis/experience/cloud-drive/content/nodes#Filtering