Hello,
When using a derived table that contains liquid expressions in my .view file, I discovered that the filters didn't' show any suggestions. Apparently this is because Looker selects the suggestion from the original table in BQ using a distinct clause.
You can solve this issue in the filters options from the dashboard (not the explore view). Even though you can't see the suggestions in the explore screen, save the explore to a dashboard. Once you're in the dashboard scree, click on the 3 dots to get the filters options and select the checkbox that indicates "Select filters to update when this filter changes".
When this option is selected, after changing the values in the indicated filters, the others will be recalculated, showing back all the available options.
Hope this is useful.
Alejandro GL
Thanks for sharing Alejandro. Just to call out that you can also use suggest_dimension and suggest_explore to tell Looker where to get those filter suggestions from!