@ndoell Is there more than object or “mesh island” in your sculpt mesh? I think you can select islands by highlighting a mesh and pressing “L” on the keyboard. If everything is highlighted then you only have 1 mesh.
Maybe the best approach is to simplify the dynamic topology in that area, then cut out that part and close it back up.
I think there is an option in dynotopology where the more zoomed out you are the less detail gets generated when you sculpt around a part of an object.
I hope that helps.