It's great to have you here in the Community, @ESchouten.
In the new search transaction layout, you can search by transaction details like memo, amount, or reference number.
For now, you can use the global search or the Classic Advanced Search to find by transaction line.
For more detailed information, you can refer to this article: Search for transactions in QuickBooks Online.
In QuickBooks Online (QBO), you can use tags and group tags to track transactions however you'd like. You can check out this article to know more: Tag transactions in QuickBooks Online.
Please let me know if you need further help with the search feature. I've got your back.