Something like this should work $.getAccounts.accounts[?(@.sourceId=='<alertOps-source-id>')].attributes.last_login_date. Replace <alertOps-source-id> with your source id.
If I am assuming the use case properly, the above wouldn’t work. Since you are using multiple identities/accounts, you may need to do a loop to iterate them and complete the compare. Note: Loops are limited to 100 items. If you have more than 100 accounts, I’d advise to filter the loop input or use a recursive approach.
Can you please provide a detailed explanation of your use case?