In the SharePoint Get Items action, under Advanced Options there is a Filter Query setting. But it appears that this has not been implemented yet. At least I cannot get it to work, and it other posts several people have indicated that the feature is still in development. Please provide a timeline and escalate this.
Ideally, it would be vastly preferred to implement this in the main UI so that each SharePoint column had a field displayed so that we could do basic "equal to" filtering without using oDATA filters. But in the meantime please implement the existing Filter Query feature.