I’m really not sure to understand your question (given that the title mentions iOS but you’re talking about Mac )
So, assuming your vault is open in Obsidian on Mac and your local notes/files in it are currently accessible and the sync method you chose is properly set up you could:
Click on the vault’s name at the bottom of the left sidebar and select the option Manage vault . This will open the Vault Switcher in which you should be able to see the path of the location of your vault on your Mac .
Next to the name of your vault (at its right) in the vault switcher, there’s a “More options”/“3 dots” (•••) menu which when clicked on will provide a Reveal in Finder option you can select… Finder will then take you to the location of your vault
Another way to locate the emplacement of a vault/notes/files on Mac is using the option Reveal in Finder available:
When right-clicking on a note/file in the Files explorer of your vault
And if you are using Obsidian Sync, please make sure to not store your vault in an iCloud folder. Mixing two sync tools together can cause file problems (sync conflicts or lost data).