You can search multiple keywords with something like this: label:robotics + label:machine_learning in the author search. Narrowing by country can be trickier. You can potentially narrow by the email address. For example, if their profile is verified with a UK email address it will end in `.ac.uk`. Thus you can search: label:robotics + label:machine_learning + .ac.uk and only get UK researchers. You'll probably get some false positives and negatives with this technique so it's not perfect but will help narrow the scope. Here's a related question pertaining to narrowing country on Google Scholar: https://academia.stackexchange.com/questions/59681/google-scholar-how-to-exclude-some-countries-from-the-search