Problem: I am not able to find any fields from my Repeatable Field Group (RFG) when I try to select a dynamic source for a Block.
Solution: If you want to loop over RFGs, you'll need to use a View. Some blocks are designed to work with fields that allow multiple values, but not individual fields in an RFG. The type of block you are trying to insert will determine which type of "repeating" field is allowed for dynamic sources.