I’m guessing @farhan wants a text list of all the command lines of the 630 nagios checks.
If you want a listing of all the Nagios rules, just go to Setup > Services > Other services > Integrate Nagios plugins. You will get listings per host folder.
When the command line doesn’t begin with a path, it runs a check from folders @Dirk mentioned. Otherwise a path is shown.
If you want those listings offline as text for analysis, or whatever, you can use a browser extension like Table Capture for Firefox, Chrome and Edge to copy tables as tab seperated data to clipboard.
A table like:
Can be copied with that browser extension to get something like this:
Actions Conditions Value Description
No conditions Service description: SNMP Kyocera Model <> Command line: check_snmp -H $HOSTADDRESS$ -o 1.3.6.1.2.1.25.3.2.1.3.1 -P 2c -C public SNMP Kyocera Model
No conditions Service description: SNMP Kyocera Serial <> Command line: check_snmp -H $HOSTADDRESS$ -o 1.3.6.1.4.1.1347.43.5.1.1.28.1 -P 2c -C public SNMP Kyocera Serial
No conditions Service description: SNMP Kyocera Device <> Command line: check_snmp -H $HOSTADDRESS$ -o 1.3.6.1.4.1.1347.43.5.1.1.29.1 -P 2c -C public SNMP Kyocera Device
No conditions Service description: SNMP Kyocera System <> Command line: check_snmp -H $HOSTADDRESS$ -o 1.3.6.1.4.1.1347.43.5.4.1.5.1.1 -P 2c -C public SNMP Kyocera System
Put the data in your favourite spreadsheet tool, for filtering, or whatever you want to do with it.