MongoDB: Set the value of array element from values another array

[polaroids.of.tarkovsky (Сергей Воронин)]

@polaroids.of.tarkovsky

I want to create a new array methods.linkToRegistry from methods.settings.linkToRegistry, i.e. I go through all the settings elements and extract data from the linkToRegistry fields into a new array methods.linkToRegistry . The only condition is to skip empty linkToRegistry elements (optional, but desirable). Accordingly, for each methods element, the linkToRegistry array must be different. But I can only do this:

Mongo playground