Does the "Manage Conditional Formatting" dialog apply to individual sheets or the whole document?

Hi all,
I am brand new to LibreOffice (trying to jump off the Google ship), so I apologize if this is an obvious misunderstanding:

I have a spreadsheet with two tabs (“sheets”?), and I would like to have different conditional formatting rules for each. In Google Sheets, this would have been done by simply setting the ranges for each rule in each sheet, no need to even reference the sheet name in the range ("$‘SheetName’.$A$30", etc.).

It seems (based on the questions I’ve seen here already) that conditional formatting only applies to one sheet and needs to be manually copied to other sheets. In my case however, it seems my changes to conditional formatting on one sheet are affecting the whole document.

To be pedantically specific in the hopes of zeroing in on the issue: If I open the Manage Conditional Formatting dialogue and make a change on one sheet, then close it, move to the other sheet, and open the same dialogue, the changes are affecting both sheets. I tried specifying the sheet name in the range, but it seemed to just get removed and only kept the cells specified.

Is there something about the logic of the Manage Conditional Formatting dialog I’m misunderstanding?

Thanks in advance for your help,
Nelson