My WordPress website consists of two separate WordPress installs (one lives in a subdirectory). From a visitor's perspective it feels like one single website. To achieve this I had to manually replicate the navigation menu of install A in install B.

Since we have a lot of changes on our website, we are looking for a solution that reads the custom menu from install A (preferrably over the REST API) and displays it as a custom menu in install B. Is there a way to achieve this easily?