Search/Filter RecyclerView from Toolbar (Sqlite Database)

I want to add a SearchView to my Toolbar, in order to search/filter items in the RecyclerView, in a fragment. The RecyclerView gets the information (image and text) from Sqlite Database. I've tried implementing the code based on this answer: How to filter a RecyclerView with a SearchView but it doesn't work for me. Does anyone has an example on how to implement filtering/searching on a RecyclerView?