Can I create a record with transaction lines based on saved search? Or perhaps populate a memorized transaction with the saved search results using workflow?

You can transform a record into another record using the transform record action (like make an estimate and transform into SO or Invoice) Then use the create line action to add one or two lines to the items sublist

super. thank you, @MGBC!

@MGBC is it possible to create a record by referencing the transaction lines of the base record? For example, credit memo to invoice.

@Luis I'm not sure what you mean? Like create a custom record for each line item on a transaction?

Sorry I meant copy the details including the transaction lines of a credit memo to an invoice via workflow after clicking a button

No credit memo does not have the transform action available for it