I am asked to see if we can download data from the ‘Supplier Transactions’ tab on the supplier. I checked for the same but could not enable the option to download this data. Then I tried to replicate the same with a saved search. However, I am not able to get the correct fields for ‘source transaction’ and ‘Original Transaction’ fields. Can someone please help? Thanks in advance.

You'll be wanting to play around with "Created From"/"Applying Transaction"/"Applied To Transaction"/"Billing Transaction"

Are you sure that tab isn't a custom tab in your account that is already a saved search?