The easiest multi-layer field op can be thrown by one or two agents in a small to medium area with minimal congestion. The easiest way I have found is for both agents to key farm the spine together and also get multiple keys to each anchor. One agent will begin the field by first connecting to the opposite anchor and then to each portal on the spine. I normally like to connect to the furthest spine link first as it helps block for the interior layering. After agent one connects their links, the second agent can proceed to throw their links in any order they choose … Again throwing to the furthest spine link first helps to block for the interior fielding. Since agent two is throwing from an anchor portal, the order is irrelevant.
Once the field is completed, agent one could flip the portal and throw the field again by first linking to the opposite anchor and then closing out each field by linking to the spine. To throw the field twice where each agent gets one score, agent one needs two sets of spine keys and two anchor keys. Agent two would only need spine keys since agent one has already closed the link to their anchor. Optionally agent two could close the anchor link as well.
If you want to increase the number of rethrows, you need to move your anchor after each flip. Since you cannot flip a portal again for one hour after using a flip card, you will be stuck with one throw unless you relocate or wait an hour. If you have planned the rethrows, you will find an anchor very close to the first one. You should connect one link to the opposite anchor before dropping the first multi-layer field …. This will help preserve the lanes from getting blocked when the field drops. If you are in a fairly remote or low action area this is not completely necessary.
happy hunting !