Okay, I found an answer myself. To help people who will read this in future, this is what I did:
1) This explains how to add a column: http://www.deluxeblogtips.com/add-custom-column/
2) This explains how to add a sortable column: https://wordpress.org/support/topic/admin-column-sorting/
Related Posts:
- How do I set the default admin sort order for a custom post type to a custom column?
- How can I change the admin search posts fields?
- Admin Area Custom Type Search By Meta Fields Without Title & Content
- Add “Last Edited by” column to custom post type list table
- How to add custom columns to Custom Post Type admin screen
- manage posts custom column is not populating data from meta boxes
- Prevent reload confirmation after AJAX save
- Custom admin columns for ALL custom post types
- How to show custom (checkbox) field value in admin post list?
- Custom post admin filtering by post meta (the date)
- Admin Column Text Positioning
- Adding HTML tags or css classes to admin columns
- CPT Columns doesn’t show categories
- Make a custom column sortable by a value from a different custom post type
- Default custom column to off
- Change column of row action (Quick Edit) links in WP_List_Table
- How to show first name and last name in custom post type columns
- Plugin – Combine Meta Box Input Fields into single saveble record
- Two Custom Post Types Many to Many Relationship
- Show custom post type relationships by taxonomy
- get_post_meta not working on publishing
- Query custom post type with ACF Date
- Custom setting to show or hide field
- Custom Meta Field – Remove comma from string with str_replace
- Store CPT ‘Reviews’ average ratings to a WordPress DB table or to a DB custom table?
- Using custom field content as expression in IF statement [closed]
- Meta Query Not Returning Output Despite Having Matching Values
- Options page – dropdown of users
- How to create a custom post type with additional fields?
- Callback to custom field is not working in WordPress REST API
- Meta Query Filtering not working on Custom Meta Box using Radio Buttons
- Including metaboxes from custom post types in global search — continued
- ACF From & To Date Validations
- How do I set all of a particular post meta to a value within the custom post type I’m in?
- Query Multiple Custom Posts by Custom Fields
- Show image gallery from a custom field
- Using advanced custom fields from one custom post type in another custom post type / using nested shortcodes
- Dynamic dropdown select values depending on other custom field value
- How to render a custom post type template with custom fields using shortcode
- Disable saving posts as draft (make all posts mandatory regardless of the post status)
- Grouping metadatas into one
- Tracking changes in admin-page so user gets warning when leaving the page
- filter custom post in rest api with custom function
- Get Posts by multiple custom fields is not working
- Woocommerce custom field search in custom post type [closed]
- No Permission to add new Page, Post or CPT with Admin role
- Add custom field in comments form
- Custom Fields for Custom Post [closed]
- Order Custom Post Type by Custom Field Value
- Filter custom post types by a field value
- Displaying All Posts of a Custom Post Type in WordPress Multisite Backend
- Repeatable Fields Metabox with Textarea (or wp_editor)
- How to use TinyMCE Editor for one of my custom post meta field?
- Custom REST endpoints for a custom post type with custom fields
- How to Create a WordPress Plugin With Custom Post Type/Custom Field Features?
- Hierarchy and access control for Custom Post Types (CPT)
- Admin Column does not populate with data
- Custom fields (wp_post_meta) vs Custom Table for large amount of data
- How to integrate a form (Ninja Form or Contact Form 7) with Custom Post Types?
- First custom field value (out of several) displayed twice after query
- Homepage’s content is dependent on the custom field values (set automatically), how do I get homepage to update without manually updating page?
- Meta Query posts not showing on ending date of custom field
- Cannot save CPT meta box
- Cross reference custom post types
- Adding Page Templates to post but it ignored it
- Order a custom post type admin screen by a second custom post type title
- Filtering posts list table
- CPT Validation to not show “Post updated.”
- Include related custom fields from one post type in another post type’s JSON feed
- Admin Custom Meta Box – Pull Last 5 Posts from Custom Post Type
- Edit Custom Post Type on Custom Admin Page instead Post Admin
- frontend image post uploader
- Is there any way to add a “custom field” to the CPT archive page?
- How to Output which matched meta_keys were found from custom_type_posts?
- Multiple Frontend Filters Using Advanced Custom Fields
- WordPress make Grandparent and great grandparent filterable in custom columns
- Custom Post Fields at the beginning of a Custom Permalink
- Integrate Custom Post Type Events into Calendar
- Possible to filter custom post type with multiple meta data?
- Hierarchical custom fields
- How to get a custom field value of a custom post?
- Fields for different parts of a page
- Is it possible to activate customfield ‘text description’ upon activating the customfield ‘checkbox’?
- Facebook social publisher and custom post type fields [closed]
- How to display products name in a non-alphabetical order, in a custom field (taxonomy)?
- Displaying custom field according to date
- Displaying and searching Custom Posts
- Importing Data from a Non-WordPress database, into WP
- custom comments form for custom post type
- Searching Custom Fields
- Show fields based on taxonomy selection in editor
- filter search custom field query
- Permalinks: custom structure for taxonomy – tags?
- How to let users choose where to search for posts?
- don’t publish custom post type post if a meta data field isn’t valid
- WebP Fallback for Inline Background Image in Style Attribute
- Query based on custom fields start and end date
- How to add multiple markers on the google map, at a certain meta_key and meta_value
- Custom fields for custom post type
- How can meta boxes be added to “unknown” custom posts?