Get list items by tag, plus all descendents

[nikclayton]

[This is a bit related to https://github.com//discussions/1329 and https://github.com//discussions/1018 I think, but just different enough that it merits its own discussion]

In my daily journal (one file per day) I have a list of items. The first item in the list is tagged and contains some text, the remaining items are children (or grandchildren). For example:

- #project/one This is the first item (1)
	- Indented second item (1.1)
	- Indented third item (1.2)
		- Item 1.2.1
- #project/two Some stuff
    - Some more stuff
- #project/three Even more stuff
    - ... 

Over in my folder for "Project One" I want to have a "Project One Journal" file that includes the relevant items from the the daily journal, by date. I..e., suppose the above example is in a file called "2026-01-03" I want the query output to be:

- 2026-01-03: #project/one This is the first item (1)
    - Indented second item (1.1) 
	- Indented third item (1.2)
		- Item 1.2.1

Where the "2026-01-03" is a link to the journal file.

This feels like something that should "just work" (or possibly I'm using Obsidian wrong, and I should structure my data slightly differently to make this easier).

Here's what I tried that doesn't work, and why (assume all of these are in fenced blocks tagged dataview):

Option 1

Query:

list item.children.text
from #project/one 
flatten file.lists as item
where contains(item.tags, "#project/one")

Output:

- 2026-01-03:
    - Indented second item (1.1) 
	- Indented third item (1.2)

Wrong because: It's missing the first item, and the grandchild.

Option 2

Query:

list list(item.text, item.children.text)
from #project/one 
flatten file.lists as item
where contains(item.tags, "#project/one")

Output:

- 2026-01-03:
    - #project/one This is the first item (1)
    -     - Indented second item (1.1)
          - Indented third item (1.2)

Wrong because: (a) that's not a typo, there are two bullet points on the third line, (b) it's missing the grandchild.

Works

Inspired by the discussion in https://forum.obsidian.md/t/displaying-all-item-information-file-lists-text-including-multiple-children/78654/6 I adapted the code there slightly.

In a dataviewjs code block put:

const dvF = dv.evaluationContext.functions

// Create a new DQL function
dvF.listWithChildren = (ctx, item, offset = "" ) => {
  let result = ""
  if (offset == "") 
    result += item.text + "\n"
    
  for (const child of item.children) {
    result += offset + "- " +
       (child.task ? `[${ child.status ?? " "}] ` : "" ) +
       child.text + "\n"
    
    if (child.children.length)
      result += dvF.listWithChildren(ctx, child, offset + "  ") 
  }
  return result
}

This adds a new listWithChildren function so I can call this from multiple places in my vault.

To use it I write (dataview block):

list listWithChildren(item)
from #project/one
flatten file.lists as item
where contains(item.tags, "project/one")

and that gives the expected output.