How to pass Block ID to a view?

I have a Custom Block type called HomeBlocks. This bundle has a paragraphs field which allows multiple paragraphs.

I then place (using Layout Builder) an instance of this block type on my home page (a node type called Landing Page). In the layout of the block type I have a View which lists some of the paragraphs added to that specific block. The view lists my paragraphs but lists all the paragraphs of that type. If I add a contextual filter for Parent ID to the view and set as Fixed with the value being the BlockID of the block which I placed on my home page; then it filters to only the ones added to that block. Perfect.

The question is then; how to dynamically set this contextual filter?

I can think of 2 approaches:

1. Create a contextual filter plugin which passes the BlockID.
2. Pass BlockID from the Layout to the View.

I looked at option 2 a while back and found some work being done to allow arguments to be passed back from LB; but it was only supporting static values (as opposed to tokens).

Option 1 seems pretty simple and I set that up. To start with I simply pass back the static ID value and this works as expected.

The missing piece here is how to get a list of blocks (of a certain type) which are placed on a specific node?

I tried doing this with a view and I can get a list of BlockIds of all the blocks of this type; but can't see how to filter to the the one used on the specific node.

If there will ever be only 1 instance of this block used on the site; then I can use my existing view (that lists the only block of this type). I am not concerned about having multiple versions of this block on a single page; but I am trying to accommodate that there could be multiple pages with this block added.

So if I understand correctly, here's what you did:

1. Created some paragraph types.
2. Created a block type, with a paragraph field referencing the paragraph types in #1.
3. Created a view with a Block display of Paragraphs, with a contextual filter for Parent ID.
4. Added the view in #3 to a display of the block type in #2 via Layout Builder.
   • I'm assuming you have other things going on in the layout, otherwise, this would simply just be a View Block of Paragraphs or just added the paragraph field directly to the layout.
5. Created instances of the block type in #2 and added them on a page.

There's a couple of crucial steps that are easy to miss:

• In step 3 (creating the view), create a relationship to the Block entity type. Then, instead of creating a contextual filter for the paragraph's Parent ID, create a contextual filter for the related Block's ID field.
• In step 4 (adding view block to layout), when you add the View block onto the layout of the block, Layout Builder will ask you about the block title and its visibility. Right after that, and because of the previous changes to the view, it will now ask you what value to pass as the contextual filter value. There will be an option that represents the current block.

The end result should be a view inside the layout of a block filtering paragraphs by the ID of the block that contains it.