Hi graham-sheffield,
Thanks for joining us here on the Community. :waving_hand:
Yes you can split transaction and enter a different memo on each line, to do this using an expense simply select + New > Expense > Fill in the payment details and scroll to 'Category field' or 'Item field' and begin filling in the lines - as you add lines here you'll see more automatically appear beneath, so you can add as many lines as needed.
Please get back to us below if you have any questions!