Hey @Sahiru_Gunawardene, welcome to the discussion boards!
Give this syntax a try. I do want to caution you though -- this is widely considered unsafe, as you are taking data from the URL (which the user controls) and injecting it into a SQL query:
filters
| essql
query={string "SELECT project, release, sum(effort) FROM my_index where field= '" {urlparam param=varFromURL default=1000} "' group by field1, field2"
| table
| render