The relationship for tags and hierarchy positions has to be 1:n, i.e. each tag can have multiple parents or none. E.g. “Historical Complexes” can also have a 2nd parent “History”, which is a child of “General Interest”
So I think you’re saying that Logseq should support polyhierarchies. That is when a child can have more than one parent.
So on a website, you could find an iPhone by clicking on “Electronics”, “Smartphones”, “iPhone”, to get to a target page, like “iPhone 7 Refurbished”. But up at the top level of the hierarchy with “Electronics” there could also be “Apple” and you could go from “Apple” to “iPhones” and get to the same target “iPhone 7 Refurbished” page by that route.
“Electronics” would be in a “by Department” facet array, and “Apple” would be in a “by Brand” facet array in this example.
All items also appear under their parent categories, so when I click on “Writing Projects”, it will link to all pages under this category. The reason for this is that one should not have to go to a folder at the bottom of a hierarchy to find an item
I’d like that too. That’s why I suggested a system-generated hierarchies page nonetheless be (almost) like an ordinary page, so you can be looking at parents and children to multiple levels of depth in one view. Is that what you mean? Maybe I’m not following you properly - or maybe I haven’t played with nested tags enough in Logseq. I did in Obsidian more.
As a generalization of the tag system, Logseq could implement nested searches.
Some of what you say makes me think again of the idea that a hierarchy is really a type of query that gives you a filtered view of a subset of your graph.
The underlying knowledge object is a graph with no top or bottom, but the nodes are constructed throughout outlining and indenting, which are mini hierarchies. It’s like the molecular/local structure is hierarchical even though the molar/overall structure isn’t.
Over time, the knowledge graph we use to store all our thoughts in loses any molar/overall hierarchical shape, but humans still use hierarchy and categorization to organize their thoughts at times. So picking a hierarchy as a lens for viewing as much of the graph as falls into its scope is a valuable view to offer.