I am working on my P0 goals for this half however, the XFN is not communicating well. I am done with my changes and blocked on them for days. They don't review code as fast as I need and keep me waiting. How should I approach them? Also, I want to build good relationship with them for a good Performance cycle feedback. I think they don't take me seriously. what is the right approach here?
Sorry to hear about this - I imagine that this is very frustrating.
First, I recommend going through the following Q&A and all of the connected resources in the responses: "How do I ask XFN partner for help to make progress in the project?"
That discussion covers several approaches you can use to tackle the problem alongside some advice about how to properly operate within this landscape in the long-term.
I think they don't take me seriously.
When I perceive something like this, I always start by looking inwards instead of outwards. This is because it is much easier to alter your own behavior than that of others.
So let's go back to this statement. What could be the reason that your XFN peers don't take you seriously? Here's some things within your control that you could optimize:
It's very possible that these XFN partners are simply very hard to work with, and you need to escalate the issue to your manager to get the ball rolling. But before arriving at that conclusion, really take the time to introspect on how you can become an XFN champion yourself. Maybe there's something you can optimize about your behavior that will bring these other parties to the table.
Also, since it is not clear from your question, I'd recommend spending a few moments to evaluate whether it is just you, personally, experiencing poor communication from one or more XFN partners, or if the entire XFN team is plagued by poor communication. If the latter, then that can signal misalignment across different teams/job functions, and you'll need to leverage your TL/manager to help resolve that.
If you think it is just you, then Alex covers that in his answer really well. The only thing I would add is to make sure that the person you are expecting code reviews from is actually aligned that they are in a critical path for your p0 goals and have the bandwidth and are committed to support you with reviews. Set up a 1-1 and talk to them, so that you can understand their PoV!