This members-only tutorial provides the steps to use Advanced Custom Fields to set up a HappyFiles category selector so that images from the selected categories will be shown as a gallery on Pages or Posts etc.
Categories in Media Libary:
Selecting one or more categories when editing a Post:
Post when viewed on the front end:
Step 1
Installed and activate ACF and HappyFiles.
Go to Media > Library, create your desired categories and drag images into them.
Go to Custom Fields > Add New and create a new field group having happyfiles_category Taxonomy type of field.
Ensure that the return value is set to Term ID.
Set it to appear at your desired location.
Step 2
Edit the Oxygen Template that applies to your post type, in this example, to all the posts.
Add a Code Block component where you want to display the images from the selected categories for each post.
Set Width to 100%.
PHP & HTML: