Hi! The relations UI definitely lets you add overlapping relations and attach one token to multiple different other tokens or even to itself. You can try it out here: https://prodi.gy/demo?view_id=rel_bio
Prodigy v1.11 also supports annotating overlapping spans: https://prodi.gy/docs/span-categorization
However, there's currently no support for overlapping spans and relations, as this gets really complex and there's often a better and more efficient way to frame the task if you end up with this level of complexity. You can read more about this here: Using rel.manual with nested entities. - #2 by ines