The syntax looks fine.
I will write a few validation steps to help you.
Check your logs to see how Search Queries look like.
For my token configured in a following way:
I've got the following query:
12996 19:42:15 INFO ExecuteQueryAgainstLucene (sitecore_sxa_web_index): +_latestversion:1 +(+(+_path:0dae33a26f53473e8abdb054d9bf3b75 +searchable:1) +test:de30ff2da089418bb4922855609a3537)
Notice this part:
My context item where I execute the query from:
If your field is not in a query then it means that your context item does not contain this field. If it does and it looks good then move to a next step.
Check index content
Make sure that your field is stored in the SXA index.
You can find your index against which you fire search queries when you open chrome dev tools:
My field looks like this:
Values in the index must be "comparable" with those from search queries.
If for example, your
category field is a computed field, it will not work (normalized raw field value from an item has to be comparable with values in the index).