You can find "Spotlight indexing" in MoneyWiz Settings (gear icon in the menu). It's enabled by default.

While enabled, MoneyWiz allows your operating system to "index" your accounts, account groups, budgets and budget groups. It means that whenever you use Spotlight, you might see parts of your MoneyWiz data in the search results. Disabling this setting will prevent your MoneyWiz data appearing in the results.

Remember -- all this indexing is performed locally, on your device. You can read more about using Spotlight in this Apple document for Mac and this for iOS.