In a layout resource XML, I have 3 RelativeLayout(s) which are inside a main RelativeLayout. The view will be shown vertically. These 3 RelativeLayout() are set next to each
You can use Horizontally oriented LinearLayout Manager in the Recycler View, and place each RelativeLayout in each item, of its Adapter.
The Link: How to build a Horizontal ListView with RecyclerView?
If your RelativeLayouts are set to a fixed width and height, that is to the size of the Screen, that you can get from DisplayMatrics, that will be OK.
The Link: Get Screen width and height
If the contents of your RelativeLayouts are different, then you can use getItemViewType() method.
Please see: How to create RecyclerView with multiple view type?
Happy Coding :-)