On my current project a lot of content is being tagged with a Contentment.DataList. How would you go about finding related content in the ExternalIndex ? I have a simple text search looking something like this, which works as expected:

var query = index.Searcher.CreateQuery(IndexTypes.Content);
    var queryExecutor = query.ManagedQuery(searchTerm);
    var results = _publishedContentQuery.Search(queryExecutor);

Could this be modified, so instead of text it is comparing the tags of the current document, with similar tags in the index ?

Maybe a starting point here.. https://dev.to/jemayn/the-problem-of-referenced-content-in-examine-indexing-umbraco-11-4355