Without much info, I would suggest this
search * | stats count by f1, f2 f3, f4
| appendpipe [| stats sum(count) as count by f1,f2 | eval keep=1]
| appendpipe [| stats sum(count) as count by f3,f4 | eval keep=1]
| where keep=1
Your question is not very clear, but perhaps you are looking for eventstats?
That would allow you to run multiple stats commands over the data in different ways.
Or perhaps you want to combine your count with an eval statement? Examples are in previous posts or the documentation
The above will allow conditional counting
can you elaborate? maybe add some sample data and use case? if you have an idea of how you would like your results to look like it can also be very beneficial...
to your question, you can count by as many fields you want ... | stats count by f1 f2 f3 .... fN
hope it helps