Allow terms to be reused in the same term set (so a term can be the child of two parent terms in the same termset, called "Polyhierarchy")
Currently SharePoint online only allows you to reuse terms in a different term set.
An example would be the term Financial report, It would be practical to have a broader term of Financial documents and another broader term of Reports. Some users will look for the term under Financial documents, and other users will look for it under Reports. This is what the "reuse" feature of the Term Store is designed to allow. However, SharePoint Online only allows you to reuse a term IN A DIFFERENT TERM SET. So if your term "reports" and "financial reports" are in the same term set, you are out of luck.
This problem is well documented here: http://accidental-taxonomist.blogspot.com/2016/01/polyhierarchy-in-sharepoint-term-store.html
"Polyhierarchy means a taxonomy term has more than one broader term or parent term. In a traditional hierarchical taxonomy structure, a term has one broader term (unless it is the top term, in which case it has no broader term) and multiple narrower terms. Occasionally, though, the logic of the hierarchy and the practical need to guide users down different possible paths, makes it beneficial to give a term two or more broader terms. It may appear to the user that the term is duplicated in different locations in the taxonomy, but this duplication is in appearances only, because it is the same term and thus linked/indexed to the same content, no matter which broader term path the user clicked down through."
"The support of polyhierarchy in the SharePoint Term Store, takes the notion of “polyhierarchy” too literally by insisting that the two broader terms of a term in a polyhierarchy actually belong to different hierarchies. This means that the polyhierarchy can only be created across different Term Sets in SharePoint. A Term Set is a hierarchy or a facet with a single top term. It is prohibited to create a polyhierarchy within the same Term Set. This is quite problematic, because I find that the vast majority of the time that I want to create a polyhierarhcy it is within the same top-level hierarchy for facet. "
Bourne Productions commented
Our business/technical term set is not a traditional taxonomy and I would be surprised if many ShareNow applications in the real world actually used strict hierarchical taxonomies. We are calling ours a "topical keyword tree" since it's not a taxonomy. The purpose of the tree is to assist users in locating items in ShareNow, not to scientifically classify the items. Please allow re-use of terms within a term set!
That's hilarious that functionality that kind isn't allowed! Whay it couldn't be done in same term group? We need one node under different terms in same group.
Alex Zichettello commented
Completely agreed. This is practically a basic knowledge management necessity.
Guys.... they have been ignoring this issue for years, I can only assume there is fundamental problems in the code that makes this near on impossible to change and implement.... and that’s just in a local SharePoint scenario.... imagine coding that for 365. I’m not saying it can’t be done but it would huge undertaking to develop requiring a lot to be unraveled and updated.
I love the idea - in fact I feel it would make the record management side of sp near on perfect, most things outside of the tax I can manipulate with SPFx pic
This is insanely needed! Consider needing to describe a hierarchy of nation-wide sales and supply chain facilities of various types: Every location is in a particular political jurisdiction (city/county/state) and also in a sales territory (region and market) which can cross or split political boundaries. A taxonomy of location types is also desirable. Currently this can't be done without three term sets, preventing the possibility of valuable queries like "find all medium-format stores in the Western region in the state of Illinois.