I guess your question relates to ResearchGate. Unfortunately, its search function (https://www.researchgate.net/search.Search.html?query=&type=publication) is rather simple. There are three filters for the results, but it is not possible to filter for only peer-reviewed documents. I do not know why ResearchGate asks whether an article is peer-reviewed or not when you add it manually. This attribute is not displayed anywhere. See also my reply to this related question: https://www.researchgate.net/post/Regarding_Peer_review_of_the_uploaded_articles