Flex includes a Sidebar for the collection page. Build your sidebar using blocks then position it on the left or right side of the Collection page.
Flex's Collection page sidebar is configured by adding content blocks in the theme editor. This feature includes options for a Collection list, Custom HTML, Featured promotion, Menu, Newsletter, Page, Search form, Tag filter, Tag list, Text, Type list, and Vendor list. Also include Faceted filtering, Shopify's built-in filter system, by updating to an Online Store 2.0-compatible version.
Build the Sidebar with Blocks
Click (+) Add block to add more content to your sidebar.
Collection list
Add the Collection list content block to display a list of all of your collections in the sidebar. This can be a good option to display if you want your customers to be able to access other collections while they're browsing, or if you have only a few collections and they're all related.
Custom HTML
Include custom HTML-formatted code with the Custom HTML block.
Faceted filtering
Add a Faceted filtering block to include the filters set up in your Navigation admin.
Adding a Faceted filtering block will disable any other blocks added to the sidebar. To use a combination of filters and other block types, consider using the legacy Tag filter.
Please note that the Faceted filtering system is currently incompatible with the Currency Selector feature.
Learn more about Shopify's built-in filter system
Featured promotion
Draw attention to a sale, policy, or anything else worth promoting to customers by adding a Featured promotion block.
Menu
Using the Menu option comes in handy if you'd like to display a list of sub-collections or other quick links in general. Since you can create 'drop-down menus' in your Navigation area, they would also display as 'drop-down menus' if added to the sidebar.
Newsletter
Include a Newsletter signup field to gather customer email addresses for mailing lists.
Page
If you'd like to display other page content you've created in the sidebar, you can add a Page content block.
Search form
Include a Search form in the sidebar to provide a field for customers to search your products.
Tag filter
If you've added tags to your products, you can add the Tag filter (also known as the multi-tag filter) as an option to your sidebar. The tags must be entered in the content block comma-separated, and exactly how you have them in your product admin page.
When a customer clicks on one of the tags, the collection will get filtered to only display products that contain the selected tag. All other tags in that collection will be hidden and a 'clear' link will appear. Clicking this will clear the filter and go back to showing all tags associated with that collection.
If you've added colors as tags, you can enable the corresponding color swatches as well by checking off the Display color swatches setting.
Tag list
If you add the Tag list content block, it will display a list of all of your tags in the sidebar.
Text
Add a Text content block to your sidebar if you'd like to input any additional text/content for your customers to see while on the Collection pages.
Type list
If you have added product types through your product admin pages, you could add the Type list content block to your sidebar.
Vendor list
If you have vendor labels added through your product admin pages, you could add the Vendor list content block to your sidebar.