Problem: I would like to access the fields in a RFG within the loop of the parent post type.
Solution: You can use a View of RFGs with a post relationship filter to loop over RFGs, or you can use the post relationships API to query related posts. Then use the Types Render Field API to render individual fields from each RFG iteration.
Problem: I have a custom search View with post relationship filters for City and State, but some Cities never appear in the filters.
Solution: Be sure to provide default options for all search filters like number of bedrooms and number of bathrooms, otherwise, Cities without matching Properties will never appear in the filter options.
Problem: I have two post types in a one-to-many relationship. I would like to create a custom search View of the child post type, filtering by distance based on an address field in the parent post type, and include other filters based on custom fields in the child post type.
Solution: A View of post type A cannot filter by fields in post type B, so you would have to copy the parent address field into the child posts automatically using custom code, then filter by the address field in the child post type.