This Pro tutorial provides the steps to filter the posts of a post type related to another post type based on the value of a True / False type ACF field in Bricks.
Consider this scenario:
- Practitioners CPT
- Practitioners Therapy Relationship field
- Therapies CPT
- Associated Practitioners Relationship field
- Active? True / False field
The requirement is to list all the Practitioners on a Page with their corresponding or related therapies but only those not marked inactive.
Practitioners List:

Therapies List:

Output after implementing the tutorial:

Step 1
Create your CPTs.
Create field groups for each.
Practitioner Fields:


Therapy Fields:


Step 2
Add Practitioner and Therapy CPT entries.
Edit any CPT’s entries and select the related items of the other CPT. Since the relationships have been set to be bi-directional, the other post type’s Relationship field will automatically get populated.
Edit your therapies and update those that should be inactive using the True / False type custom field.
A therapy marked as inactive:

Another therapy that is NOT marked inactive (default state):

Step 3
Edit the Page where you’d like to show the practitioners’ grid with Bricks.
Set it up like this:

Outer query loop:

Set the Posts per page to a large number.
Inner query loop:

Enable “Query editor (PHP)”.

return [
'post__in' => get_field( 'practitioner_therapy' ),
'meta_query' => [
'relation' => 'OR',
[
'key' => 'active',
'value' => '0',
'compare' => '!=',
],
[
'key' => 'active',
'compare' => 'NOT EXISTS',
]
],
];
Note: If the meta filtering is not needed, the inner query loop’s type can be simply set to Practitioner Therapy ACF Relationship.