Can someone please give a simple explanation of what the portfolio level and value stream levels mean in SAFe Agile. I understand the program and team level. But I am having a tough time wrapping my mind around the first two levels. A simple explanation and/or an example would help alot!
There's no such thing as a "value stream level" in SAFe. The four levels in the current version (4.6) of SAFe are Team, Program, Large Solution, and Portfolio.
Team is simple - it's an single cross-functional team working on a single product or service. The Program level is a team of teams working on a single product or service. A Large Solution is a group of products or services aligned on a common vision. A Portfolio is an organization's suite of products and services, some which may be part of a Large Solution, some may be supported by a Program, and others may be supported by a single Team - each Value Stream is one of these lower levels.
But I'd also echo Ian Mitchell's comment - SAFe is incredibly complicated. Perhaps overcomplicated or too complicated for organizations. But that doesn't mean that it has good ideas. I've found the different levels and contexts to be useful to think about, along with some of the constructs. But SAFe also feels like it supports traditional management techniques, especially at the higher levels.