We have a D8 site with a view that links a Content-->Paragraph-->Content. We also have language translation enabled so the views_ui module displays duplicate rows for all combinations for the content languages. The simple solution would be to modify the view query with something like;
where (content1.langcode = paragraph.langcode) and (paragraph.langcode = content2.langcode)
Unfortunately it seems that hook_views_query_alter only allows modifying the "where" clause of the query to compare a "field" to a "value". Is there any syntax to compare a "field" to a "field"?