How can I filter information of sales, by user or employee?

Good day, lacteospueblovie.

I'll help with your question about customising sales reports. You can customise the Sales by Product/Service Detail report and add the for Created by a column. Here's how:

1. Go to the Reports menu and look for Sales by Product/Service Detail.
2. Click the Customise button in the upper-right hand corner. 
3. Scroll-down to the Columns section and check the box for Created by.
4. Click Run report.

You can also export the report to Excel so it's easier to sort the transactions. Just click the Export icon and select Export to Excel. 

More details and additional guidance when running reports are discussed here:

• Customise Reports in QuickBooks Online
• Common Custom Reports in QuickBooks Online

Don't hesitate to join us again in the Community if you need more help. We're always here to guide and assist you anytime.