Is there a way in QB online to limit a P&L report to 1 or 2 categories at a time ,as I did in the Desktop version? e.g. "Uncategorized" or "For Review"

"FOR REVIEW" are not yet in your books so you cannot pull a report on unposted activity. "Uncategorized" is not a COA but would refer to Class and yes you can filter most reports by individual class or account. Open desired report and then customize, filter

on QB Desktop I created a category called "Review" so that I would know to go back  & review that transaction, and another one called "Uncategorized."  Then on Desktop, I was able to filter a report so it only showed those items.  Are you saying that I can't run a report on categories I've created in QBO?

Thanks for getting back to us, @rosaliep.

If you mean running the Profit and Loss by Class, we can turn on the Track classes feature. This will let you assign the categories Uncategorized and Unreviewed to your transactions. 

Here's how:

1. Go to the Gear icon and select Account and Settings.
2. Choose Advanced, then click on the pencil icon in the Categories section.
3. Put a check mark beside Track classes.
4. Click Save, then Done.

Once done, run the report, and then filter it to only show the specific classes. I'll guide you how:

1. Go to the Reports menu.
2. Search Profit and Loss by Class.
3. Click the Customize button, then select the Filter drop-down arrow.
4. Put a checkmark beside Class.
5. Click Run report.

Feel free to browse these articles to help you run reports and customize in QBO:

• Run reports
• Customize reports

Let me know if you have other questions about QuickBooks. I'll be right here to help you out. Have a great day!