Posted a cash expense. Shows in my cash account and if I search supplier transactions but doesn't show in my expense transactions?

Thanks for visiting the Community today, @jackie.williams. 

To ensure that you're able to generate the Transactions List by Supplier report that shows your posted expense transactions, I'd recommend you select the correct date of the report in the Report period drop-down list.  

To know more about customising reports in QBO, check out these articles:

• Customise your reports in QuickBooks Online. It helps you learn about applying multiple filters to achieve what you want to show in the reports. 
• Popular custom reports in QuickBooks Online. It contains links to different topics that can help you learn about the various ways of customising reports. 

Feel free to get back here should you have additional concerns. We're always delighted to help.