How to build nested comments in Bubble

A nested comment system in Bubble works by giving every Comment its own field that points to its parent comment. Top‑level comments have the parent field empty. Replies store the Comment they belong to. Then you display them using a repeating group that searches for comments where Parent is empty, and inside each cell you place another repeating group that searches for comments whose Parent equals Current cell's Comment. This creates the nesting.

Data Structure

Create a data type Comment with these real Bubble fields:

• Text (text)
• Author (User)
• Parent (Comment) — this is the key
• Post (Post) — if your comments belong to a post

Top‑level comments have Parent = empty. Replies have Parent = the comment they're replying to.

Showing Nested Comments

Put a repeating group on the page. Its data source should be:

// Only top-level comments
Search for Comments
  constraints:
    Post = Current Page Post
    Parent is empty

Inside this repeating group cell, add:

• A text element showing Current cell Comment's Text
• A button “Reply” that sets a custom state like reply\_to = Current cell Comment
• A second repeating group for replies

The replies repeating group’s data source:

// Children of the current comment
Search for Comments
  constraints:
    Parent = Current cell's Comment

This naturally nests as deep as you repeat the same pattern.

Creating Replies

When the user submits a reply:

// Create a new Comment
Text = Input Reply's value
Author = Current User
Post = Current Page Post
Parent = Custom state reply_to   // the comment being replied to

Key Bubble Tips

• Use privacy rules so users can read comments from the correct posts only.
• If nesting becomes very deep, limit how many levels you visually render to avoid heavy searches.
• Always search “Parent = Current cell’s Comment” instead of storing lists — Bubble handles single references better.