If you want to:
Explore how to set up bespoke exports for your lists - say you want an export only showing dates for leave or a list of people with leave booked only (but not their dates).
Restrict what's visible in the list to certain people.
Here's a short video showing what you CAN do readily (with a little care, obviously).
NOW, THE CAVEAT ...
This doesn't really face into that example where you want to obscure leave entitlement fully. To do that would require Column level view permissions which to date, we don't have in SharePoint.
There will be creative ways around this but for now, the idea of restricting what you can see to your own items seems the safest as Mark has shown.
In the Dataverse (A database within Microsoft 365 if this is a term you haven't come across yet), you can set up unique 'Views' on Tables (data) and also assign 'Roles' to those views so there is a lot more flexibility but as of now in SharePoint, our options are somewhat limited without digging deep into permissions.
Find ways to get involved with #Collab365 here:
https://academy.collab365.com/links
Watch video 2. How to Configure List Permissions & Views in SharePoint online without registration, duration hours minute second in high quality. This video was added by user Collab365 12 October 2023, don't forget to share it with your friends and acquaintances, it has been viewed on our site 3,45 once and liked it 1 people.