Do not be surprised not to see the search radius because it will not appear when your search result gives you many options.
If, however, you are looking for a restaurant in a city where not many restaurants are displaying, you will see the radius search feature appear in the filters on the left.
If you are returning less results, you can enlarge or reduce the search radius to adjust and get more results.
To do this, just drag the arrow kilometers, to expand your search.
Remember that if you appear many restaurants in your search result and want to use this function, simply enter an address instead of the name of the city.