Hey @Matlu,
If you don't have a 3rd party tool like Tufin or AlgoSec, as PhoneBoy said, you'd need to use the Check Point Management API.
We've done this on our MDS using a bash script. The script uses various API commands to loop through each domain, and every policy package within that domain to query the rulebases for zero hit rules and extract the resultant rules into a CSV file that contains the rule UIDs, source, destination & port information. The API to query the rulebase is 'mgmt_cli show access-rulebase'. You can pass additional arguments to query the hit count of the rules within the policy, including the ability to specify from/to dates. One thing to note is that the maximum number of rules you can query is 500, so you need to recursively loop through the rulebases if they contain more than 500 rules. Here's an example output of the API call from the Check Point Management API reference guide:
mgmt_cli show access-rulebase offset 0 limit 20 name "Network" details-level "standard" use-object-dictionary true show-hits true hits-settings.from-date "2014-01-01" hits-settings.to-date "2014-12-31T23:59" hits-settings.target "corporate-gw" --format json
• "--format json" is optional. By default the output is presented in plain text.
You can use jquery to filter the hit count to only return results equal to zero.