One of the facets of poly that I continue to explore is the idea that we have more options on how to deal with changes in relationship than we would most likely have access to within a more conventional relationship model. This does seems to be pretty advanced stuff, however, even for people who actively put energy into being self-aware and not following pre-determined pathways.
Most often, if a mono dyad find themselves in a space where one or more of their major needs aren't being met within the relationship, they break up, to continue on the search for "The One" who will "complete" them, and perhaps, if they're really fortunate, be able to maintain a level of civility with their Ex. It seems far more common to have a spectacular blow up, decide that someone never really loved at all, and actively avoid ever needing to interact with your formerly indispensable partner again. Neat, clean, surgical. Cut the person out of your life and move on. Let's talk about something not nearly as black and white. Staying in.
In poly, we have more choices available to us, and can create different versions of relationships than what-has-gone-before. Particularly in interwoven chains of relationships, it is often highly desirable to minimize disruption to the entire system by coming up with a form of connection that doesn't involve flame-throwers or picking up sides!
The first question to ask is if you find value in having this person continue to be a part of your life? Do you still see more positives than negatives? Has what has gone before poisoned the well for future interactions to a degree that will not allow for forward motion? Check this carefully. Unresolved stuff is often internalized, and will continue to be present in future relationships, but that doesn't mean this is going to be the best spot for you to do that work.
There are probably valid reasons that the relationship is shifting focus. So question #2 is: Are all concerned parties still vested in working on their own shit independently and cooperatively? Just saying you want to stay important to each other on some level doesn't mean that anyone is done with the stuff that brought you to this space, so with any newly redesigned connection, there is likely to be some heavy lifting that still needs to be done to move forward into a fresh perspective together. If that seems to be in mutual alignment, great!
Question #3 may look something like this: "Well, I know that what we were doing wasn't working on some level, so I don't want that!". Oh, that wasn't a question, was it? Very perceptive of you! This is where you get to ask the question: "What do I want? What do we want together?". This may sound simple, but clearing out the patterns and habits of "what has gone before" and converting it to "what is desired now" can take a bit of effort, time, and calling bullshit on each other as needed.
Once you know what you want to create together, it becomes a matter of implementation, and, as with any relationship, there may be some bumps in the road, or it could be smooth sailing. Any way you slice it, questions 1-3 are just the starting point of a process that will continue to be refined with time and shared experience. Any relationship is a living thing that requires nurturing to stay healthy, and if you've decided that the delicate, high-maintenance "orchid" you've been nurturing together really needs to be converted to a "cactus" with lower overhead, or if you are "up sizing" a connection that has grown beyond it's original bounds, there are new skills that need to be acquired.
Remember that there can be feelings of loss or grief over restructuring a relationship, as well as excitement and renewed vigor, and remain compassionate with each other. Love is a many splendored thing, so learn to enjoy the splendor of new territory together!