Miller Columns

Browse your notes as Finder-style Miller columns — a horizontally-scrolling stack of panes where each column shows the children of whatever you selected in the column to its left. Click a note with children to drill in and open a new column; click a leaf note to open it. Use Miller Columns as a standalone view, or (on Obsidian 1.10.0+ with the Bases plugin enabled) register it as a custom view type inside your .base files.

The hierarchy isn't a folder structure — it comes from parent / children frontmatter properties on your notes, the same convention used by Breadcrumbs and abstract-folder. Miller Columns reads that frontmatter directly, so it interoperates with either plugin out of the box — no configuration required if you're already using their default field names, and no hard dependency on either one.

Frontmatter convention

A note declares its parent (and/or its children) as wikilinks in frontmatter:

---
parent: "[[Project Alpha]]"
---

Children can be declared the other direction instead (or in addition — both are merged into the same graph):

---
children:
  - "[[Task 1]]"
  - "[[Task 2]]"
---

A note can also have more than one parent — set parent to a list to place it in multiple branches of the tree at once:

---
parent:
  - "[[Project Alpha]]"
  - "[[Q3 Priorities]]"
---

Notes with no parent become roots and appear in the first column. Property names are configurable in settings (defaults: parent / children), and links that don't resolve to an existing note are skipped rather than shown as broken entries.

Drag gestures

• Drag a note onto a folder (a note that already has children) — moves it, replacing its existing parent(s) with that folder.
• ⌘/Ctrl-drag a note onto a folder — adds the folder as an additional parent instead of replacing, giving the note multiple parents.
• Drop on empty space in the root column — clears all parents, making the note a root.

Dropping a note onto one of its own descendants is rejected with a notice; nothing is written. Dropping a note onto itself is simply ignored (no-op, no notice).

Known limitation: only folders (notes that already have at least one child) are valid drop targets. A childless note can't yet be turned into a parent by dragging onto it — to give a note its first child, add the parent/children frontmatter by hand once, and drag-and-drop works on it from then on.

Sorting

Each column can be sorted one of four ways (set in settings):

• Name — alphabetical, folders (notes with children) before files.
• Thermal — most recently modified first.
• Gravity — most descendants first (biggest subtrees rise to the top).
• Rot — staleness-weighted: notes that are both old and have a large, neglected subtree sort first, so overgrown, untouched branches surface.

Settings

• Parent properties / Children properties — comma-separated frontmatter property names to read (defaults parent / children).
• Sort order — one of the four sorts above.
• Open in new tab — open a clicked note in a new tab instead of the current one.
• Use my Breadcrumbs fields — a one-click button that inspects your installed Breadcrumbs configuration and copies its "ups"/"downs" field groups into the Parent/Children property settings above, so the two plugins read the exact same frontmatter.

Use as a Bases view

Miller Columns can also register as a custom view type within Obsidian's Bases plugin (requires Obsidian 1.10.0+ and the Bases core plugin to be enabled; on older versions or with Bases disabled, the plugin still works as a standalone view).

To use:

1. Open any .base file and add/switch a view to "Miller Columns" as the view type.
2. Configure the view in the Bases view settings UI:
   • Parent property (default: note.parent)
   • Children property (default: note.children)
   • Sort — Name, Thermal, Gravity, or Rot (see above).

Scoped to the Base's query results: Only notes matching the Base's filters appear in the hierarchy. Parent links pointing outside the result set are ignored; those notes appear as roots instead.

Drag-to-reparent: Works only when the .base file is opened standalone in its own tab. When the base is embedded (![[Foo.base]] or a `base` code block), the view is read-only navigation — the same click-to-drill gestures work, but dragging is disabled. Drag a note onto a folder to move it, ⌘/Ctrl-drag to add a parent, or drop in the empty root-column area to make a note a root.

Opening notes: Clicking a leaf note opens it in the active tab. (The standalone Miller Columns view's "open in new tab" setting doesn't apply to the Bases view.)

Installation

Desktop only for v1 — the horizontal column layout and drag-to-reparent gestures rely on desktop drag-and-drop (manifest.json sets isDesktopOnly: true). It will not install or run on Obsidian mobile.

Not yet in the Obsidian community plugin catalog. Until then, install manually or via BRAT.

Manual:

1. Download main.js, manifest.json, and styles.css from a release.
2. Create a folder <vault>/.obsidian/plugins/miller-columns/ and place the three files inside it.
3. Reload Obsidian and enable Miller Columns in Settings → Community plugins.

Via BRAT:

1. Install and enable the BRAT community plugin.
2. Run BRAT: Add a beta plugin for updates, and enter this repository (nelsonlove/obsidian-miller-columns).
3. Enable Miller Columns in Settings → Community plugins.

License & provenance

MIT licensed (see LICENSE). This is an independent, clean-room implementation — it reads the same parent/children frontmatter convention as abstract-folder for interoperability, but no code was copied from it or from any GPL-3.0 project; nothing here is a derivative work.