You can append the %path% parameter to the redirect URL to generate the deep-link redirect.
With the %path% parameter at the end of the Redirect URL, the target will use the given domain and append the actual path from the source URL.
Just open the redirect widget configuration and make the following settings:
An example:
if the Redirect URL is "https://<your-german-domain>.com/%path%" and the customer visits https://<yourdomain>.com/collections/all the redirect will go to https://<your-german-domain>.com/collections/all.