Here I'm going to show you how you can exclude any folder from indexing. This is really useful if you want to exclude your js assets (bundles) folder(s) to speed things up.
I wasn't able to find how to do it from Rider UI directly, but after some search, I found that it's could be done in the internal mode.
Enable internal mode:
Help -> Edit custom properties
Go to the
Tools menu -> Internal Actions (Rider) -> Solution Structure (available only in internal mode).
Now you can choose a folder or folders to exclude from indexing.
More info here: https://youtrack.jetbrains.com/issue/RIDER-8664